[The following story is fiction, and all names used are fictitious.
If explicit adult material is illegal in your locale, if it offends
you, or you are under 18 DO NOT READ ANY FURTHER.  The story also
describes use of an electro-stimulation (TENS) unit. DO NOT TRY ANY
SUCH TECHNIQUES DESCRIBED unless you have a thorough understanding
of electrical principles and have been instructed in the safe
operation of a TENS unit!]

Shelly Heath walked into the Physio-Lab, Inc. offices a little after four p.m. on a sunny Thursday afternoon in early October. Shelly was a 21 year old junior at the nearby university, who was enrolled in the business program. Shelly was single, with no steady boyfriend at the time.

A flyer on the bulletin board in the student dorm where she was a resident assistant had asked for volunteers for a grant-funded research program attached to the university’s physiology and physical therapy programs. The flyer had announced that students were sought for two to four hours of their time so that various physical characteristics could be studied. Shelly had a bit of spare time on her hands, being the first part of the semester. Since she was athletic, she figured that the research could someday help her and others with sports injuries and subsequent rehabilitation.

Upon entering the clinic, Shelly was greeted by a receptionist, a pleasant woman maybe a few years older than her, who smiled and handed her a health questionnaire and a waiver form. After filing out the usual health history questions and scanning the waiver quickly (it all looked the same no matter what form it was) she signed them and handed them back to the receptionist. After a brief wait as she read a health/fitness magazine, a young man called her in.

“Miss Heath? Would you come in please?” asked the pleasant looking young man in a white lab coat, who Shelly mentally gauged to be about twenty years old and fit. Shelly followed him through the door to the right of the receptionist and down a short hallway. At the end of the hallway, they went through another door with a sign saying “Authorized Personnel Only.”

Inside was a larger hall that was partitioned off with high cubicle-type room separators. As they began to walk to the left, Shelly noticed a low murmur of activity consisting of various noises, grunts and low-level conversation being spoken in short sentences…almost like commands. Some of the cubicles she passed had curtains stretched across the openings, and a few did not. As she passed one open curtain, she noticed a woman on an exercise bicycle pedaling furiously and showing obvious signs of exertion. Suddenly Shelly noticed something odd…the woman was wearing only a pair of skimpy panties and was completely naked from the waist up! There were some sort of clips with wires attached to her nipples, but it was unclear what their purpose was. Calmly watching the woman was a young man wearing a white lab coat and making notes on a clipboard. Shelly was about to ask her escort what they were doing in that cube, but he suddenly pulled a curtain aside and asked her to step in.

“This is where we’ll be testing you today, Miss Heath,” said the young man. Shelly noticed that the cube was about ten by fifteen feet in dimension, with an exam table, a counter with various instruments on it, and some other devices that looked like monitors and wires, etc., on a rolling equipment cart.

“Before we start, we have to give you a quick exam to ensure you’re in good enough shape to be one of our study subjects,” the young man stated. “Please take off your clothes and have a seat on the examination table, and someone will be with you in just a few minutes,” he said pleasantly. Shelly wasn’t expecting to have to be undressed and examined, but then rationalized that since this was a physiology study, it would stand to reason that access to certain parts of her body would be necessary.

Without much of a thought, Shelly undressed down to her bra and panties, figuring that would be sufficient. She pulled back her auburn hair into a ponytail, letting it fall over her taut, youthful body. She prided herself on her fitness, and was proud of her muscle tone.

She sat on the exam table, looking around at the sundry devices, wall charts, etc., when she became aware of some muffled noises coming from the adjacent cubicle. She quietly slipped off the exam table and padded over to the corner in her bare feet, trying to listen more closely to what was taking place next door. She saw a sliver of light piercing a separation in the modular wall joint, and pressed her eye up to it. What she saw amazed her.

Off to her left was a girl who looked like she was Shelly’s own age, wearing a white blouse under shoulder straps of a dress with vertical pink stripes. She was holding a clipboard on which she was writing, as well as a small black box which she cradled between her abdomen and the lower end of the clipboard. On the floor in front of the girl, and in profile to Shelly, was a young man who was doing pushups and showing obvious signs of exertion. The boy was naked except for an athletic supporter, which gave both Shelly and the young monitor a birds-eye view of his clenched buttocks. Shelly blinked as she noticed a pair of thin black and red wires leading from between his asscheeks to the black box held by the monitor. A similar pair of wires ran to the box from underneath the jockstrap’s pouch holding his genitals.

As she pressed her eye to the crack, she could see the young man straining to squeeze out more pushups. The young girl finished writing and looked down at the boy intently.

“Keep trying, David…don’t give up. You know what will happen if you give up, don’t you?” asked the girl, with what seemed like an amused smile.

“Y…yes, ma’am,” David huffed.

‘Ma’am?’ thought Shelly. He’s calling this young girl ‘ma’am’? And what was her comment all about, anyway? Shelly was captivated by the scene in front of her, even though she didn’t completely understand it.

After squeezing out one last pushup, the boy collapsed to the floor, huffing and puffing. “I’m sorry, I just can’t do any more!”

The girl looked down at him and shook her head slightly, as if to say, ‘Oh well, there’s nothing I can do for him now.’ She repositioned the black box on the clipboard and pressed a red button. Immediately, the young man on the floor before her jumped and yelped.

“OK OK OK…..here I go…I’ll do more…” he blurted out in a rapid-fire staccato, as he pushed himself back up into the leaning rest position.

“David, you know that I’m required to discipline you if you show a lack of motivation. Doctor Peters’ orders, you know,” said the girl with a smirk.

As David remained in position, the girl moved forward and bent down over his backside. With her free hand she parted his buttocks and made some adjustments to whatever device was inserted in his rectum.

With her fascination at what she was seeing, Shelly failed to hear someone enter her cubicle behind her.

“Interesting, isn’t it?” said a female voice behind her. Shelly jumped and spun around to see a young female dressed the same as the monitor in the other cube, accompanied by a young man of about twenty-four wearing a white lab coat. Shelly couldn’t find anything to say, but now was acutely aware that she was standing there in just her bra and panties.

“My name is John,” he said, “and this is Cindy. We’re going to be the research technicians who will be testing you today.” Shelly smiled and said hello.

“Let me explain the volunteer program to you briefly,” John said. “Doctor Peters is the senior supervising physician on this project. I’m a physiology grad student at South Central University and Cindy, like others here, is a nursing student who also volunteers at the local hospital.” ‘Student nurses?’ thought Shelly. ‘Aren’t they a bit young and inexperienced for this sort of thing, especially taking charge of nearly nude volunteers their own ages?’

“Don’t be concerned with what you’ve seen so far. That has to do with the exercise physiology project. You will be part of the sensory/stimulus study project. No endurance testing for you,” he continued with a chuckle. “But first, you have to have a quick physical so we can get some baseline readings.”

Cindy took Shelly’s arm and guided her over to the scale in the corner of the cubicle. “OK, Miss Heath, I have to weigh and measure you for the record. I need you to remove your bra and panties now,” said the girl.

“Why? They don’t affect my weight at all…” said Shelly before being cut off.

“Miss, all our test subjects ask the same question. Dr. Peters requires totally accurate statistics, and our instructions are that height and weight will be taken with our subjects completely nude. Now please remove your bra and panties for me,” explained Cindy.

Shelly hesitated for a fraction of a second while she glanced over at John, then with a sigh of resignation unhooked her bra in the rear and let it slip over her arms and off. She slid her thumbs under the elastic waistband of her skimpy white panties on either side of her hips and pulled them down to her knees, bending forward slightly. She wiggled her legs until the panties fell lifelessly to her ankles, where she stepped out of them and kicked them off to the side where her other clothes lay. Now she was completely naked in front of these two young strangers.

“OK, Miss Heath, up on the scale, please,” Cindy said. Shelly stepped up on the traditional doctor’s scale where Cindy adjusted the weights on the balance beam until they showed a reading of 125 pounds. Cindy called out the weight to John, who duly noted it on his clipboard. Cindy moved behind Shelly and placed one hand on her abdomen just below her breasts and the other on her lower back just above the cleft of her buttocks where she had a dimple on either side at the base of her spine. Her hands felt a bit cool and they were smooth. It was a strange, but vaguely pleasant sensation; she couldn’t ever remember being touched like this by a young girl.

“Now, I want you to stand up nice and straight so I get an accurate measurement,” explained Cindy as she pressed her hands inward to straighten Shelly’s posture. Shelly had moved her hands forward to cover her pubic area, but Cindy had pulled them back to her sides, telling her to stand at attention. When the top bar of the scale was touched to the top of Shelly’s head, Cindy called out the height of 5’6″ to John. Shelly was then allowed to step off the scale, and went immediately to her clothes and quickly pulled on her panties and began slipping her arms through the bra straps before being stopped short by John.

“Woah, not so fast. We’re not done with the baseline vitals yet. Leave your bra off for now,” he told her. Shelly, who was starting to feel a bit more comfortable thinking she could cover up, thought of protesting, but remembered she had volunteered for this and mentally agreed to cooperate. She dropped her bra back down onto the clothes pile.

“Come on over here so we can get some vitals,” John told her. She walked over to the exam table and began to climb up, when Cindy put a hand on her shoulder, stopping her.

“We can do this all at once while you’re standing right here,” she said. I want you to face the table and bend over it. I suggest you grab the opposite edge to keep yourself steady.”

Shelly had never heard of this happening during an exam before, but she already had the uncomfortable feeling that this examination was going to be different.

Shelly faced the table and leaned over until her hands were at the opposite side. She felt Cindy’s dress brush against the bare backs of her thighs as she pushed Shelly’s groin into the side of the examination table and extended her arms fully toward the other side. With a hand in between her shoulder blades, Cindy pushed Shelly firmly down until her nipples pressed against the paper covered cushion. The cool feeling and the friction of her nipples brushing the paper caused a tingling sensation which began to embarrass Shelly. She voluntarily pressed her breasts into the cushion, hoping to hide their erectile state from the two technicians. Without further warning, Cindy’s fingers slipped under the edge of her panties and began to tug them down her legs and thighs, past her knees, and finally down to her ankles. Cindy raised the right foot and slipped the panties off of it, leaving them circled around the left ankle.

“Spread your legs wider for me,” Cindy ordered as she placed her hands between Shelly’s thighs and forced them outward until they were about two feet apart.

“What’s this all about?” asked Shelly nervously.

“We’re going to take your temperature, pulse and blood pressure,” explained John. Since we do all three at once, it won’t take long at all.”

“You don’t mean a rectal temperature? I haven’t had that done since I was a kid, for God’s sake,” cried Shelly with alarm. She began to raise up off the table and turn around to speak to John about this, but he pushed her shoulders back down and told her to stay still for the procedures or they would have to begin all over again.

“Dr. Peters insists on accuracy in all our readings, as we’ve explained. The rectal and vaginal temperatures are the most accurate and least susceptible to external effects or manipulation,” explained John. “Now, we expect you to cooperate without further fuss, OK?”

Cindy had already brought over the blood pressure cuff and stethoscope as well as several thermometers and a tube of KY jelly, setting them on the exam table beside Shelly. Shelly couldn’t take her eyes off the instruments, knowing they would soon be used to violate her private body parts.

While Cindy began smearing KY over the thermometers, John picked up a latex glove and pulled it on with a snapping noise. He used the fingers of his other hand to push down the glove between his fingers so the glove was on tight. He flexed the gloved fingers several times before holding out his hand for Cindy to squeeze some KY onto his first two fingers.

With his fingers all slick from the clear lubricant, he stepped behind Shelly and waited for Cindy to spread her taut cheeks with her fingers. Shelly could feel his warm breath on her fine anal hairs, he was so close, and she could feel her face turning red with embarrassment at having complete strangers see her most private hole up so close. She suddenly felt the cool KY on the tip of his gloved finger lightly touch the outside ring of her anus, moving in small circles all around the outside edge….then slowly finding the center of her target. His fingertip began pushing in past her sphincter.

“OHHHHHH……do you really have to do this? I don’t think I can take this,” whined Shelly as she began to squirm.

“Yes, Miss Heath, I have to lubricate you for the thermometers. Otherwise they won’t insert comfortably and you’ll complain about that, too. Just relax and let it happen,” instructed John. Seeing that Shelly was getting restless, he turned to Cindy.

“Cindy, go around the table and hold this lady’s shoulders down for me, would you? I don’t want her squirming around so much while I’m working.”

Cindy went around to the opposite side of the table where Shelly’s head was and took hold of her shoulders. Shelly looked up at the young girl’s eyes, and caught the sense of glee at being able to force this on her. The girl had a surprising strength, and Shelly felt her breasts being pushed into the table cushion.

As she was being held down, Shelly felt her cheeks being parted again, and this time the tip of the thermometer remained poised at the entrance to her rectum. She felt the cold silver bulb of the tip touch dead center on her wrinkled hole and scrunched her anus in response. After the initial “wink” reflex, she felt the thin glass tube enter her behind…going in all the way. She thought that would be it, until she felt another thermometer being inserted in her rectum.

“What…?”

“Relax, Miss Heath, this is standard procedure here. We have to use two thermometers to verify readings,” said John as he cupped his hand across both her buttocks and over the ends of both thermometers. Shelly was apprehensive that this was beginning to go too far, but in spite of that, she felt some stirring in her groin. Oh, God, how could she be getting aroused at a time like this?

After four minutes was up, John slowly slid one thermometer at a time out of her puckered hole and recorded the readings. Almost as an afterthought, the told Cindy to check her nipples.

“Cindy, would you check her nipples for me, please? You know what the sensors are like…see if they’ll fit on her.”

Cindy motioned for Shelly to lift her chest a bit, and slid her hand, palm up, under her hanging breasts. Slowly, she worked her way around each breast until she felt the nipple. She took each nipple between her thumb and forefinger and rolled them back and forth. Shelly’s nipples were tingling before, but now they were rock hard and perfectly erect.

“I think they’ll fit just fine, John,” she reported. “They’re very responsive and seem long enough to fit into the terminals.”

John finished making his notes, then returned to Shelly. “OK, now I want you to hop up on the table and lie down on your back for me.” Shelly was only too happy to get out of that humiliating position and assume a supine position on the table. She felt relaxed now, feeling the flexible cushion and clean white paper underneath her bare posterior. She placed one arm over her breasts and the other hand over her pubic mound, somehow thinking that her modesty was being restored.

As soon as she assumed the position, John ordered her to move her bottom down to the edge of the table and place her feet in the stirrups. She hated that position, remembering how exposed she was during her regular gynecological exams. She took a deep breath and slithered her butt down to the end, and one by one raised her legs to rest them on the full-length stirrups. John adjusted them so they brought her knees back toward her breasts and raised her feet. Then he opened them wide, so she was completely exposed. Shelly had never felt the rush of cool air on her asshole and pussy at the same time like she did now. She saw Cindy shaking down another thermometer, and wondered what that was for.

“Wait…you just took my temperature…” Shelly blurted out.

“Yes, that was the rectal temp. We are also required to take a vaginal temperature as well to confirm the readings and add to our database,” Cindy explained. “Don’t worry, it’s painless.”

Cindy went to the edge of the table and got right down between Shelly’s legs. She spread her puffy lips nice and wide, then inserted the thermometer until only about an inch protruded. While the thermometer was inside, Cindy and John both did an external examination of her genitals. They spread her lips apart and examined the pink, wet inner lips, poked and probed and spread open her peehole, and finally found her clit. They pulled back the skin covering the little button and exposed the slick pink swollen organ. John grabbed it between his fingers and squeezed it slightly, causing Shelly to twitch her hips. Cindy giggled and told John to quit it, as they would see enough of that later. Shelly was certainly excited…obviously related to the fact that she was naked and exposed to these two young people. But she was becoming more embarrassed and wasn’t sure she wanted to continue with this project.

When time was up, Cindy removed the thermometer and read the temperature to John, which was again normal. John looked satisfied as he reviewed her chart.

“OK, Miss Heath, we’re going to wire you up for a few experiments now. We want to get to the heart of our testing without further delay.”

“What experiments? I don’t think I want to continue as a volunteer here,” retorted Shelly as she began to get up off the table.

“Miss Heath, in case you don’t remember reading the forms you signed earlier, let me refresh your memory,” said John with a casual air. “Right here above where you signed, you agreed to complete all testing required. Also, you gave us sole discretion as to what the procedures would be and when you were to be released. In other words, you’re our captive subject as long as we need you.”

Shelly looked at him, then at Cindy, who just smiled and nodded in agreement. Of course she had not read the forms…but she couldn’t believe that she was being forced to stay here and endure this humiliation. She began to protest, but John wasn’t even listening.

“Cindy, get the straps. She’s going to have to be restrained,” John ordered. Cindy trotted to a cabinet and produced several leather straps with brass buckles on them, as well as some leather wrist and ankle cuffs. She got back just in time to help John, who was tussling with Shelly to keep her pinned on the table.

With Shelly protesting loudly, Cindy held her arms and legs as John wrapped the cuffs around her wrists and ankles. After fastening each extremity, Cindy ran the straps to metal rings on the sides of the examination table. Shelly’s arms were immobilized at her sides, while her legs were secured to the stirrups. John placed a firm cushion under her hips, raising her pelvis off the table a few inches. They finally secured their subject with two straps across her torso; one just under her breasts and one across her lower abdomen. Satisfied that Shelly was now totally immobilized, they set about their task in earnest.

“Is this necessary? Puleeeze let me go. I’ll cooperate if you just take these straps off…..” Shelly pleaded.

“Now, now, Miss Heath, no more fussing. If you persist in making a scene and disturbing others here, I’ll be forced to gag you as well,” said John flatly. Shelly closed her eyes and gritted her teeth. Anything but being gagged!

“Thank you. Now, we’re going to do a study on comparative responses between males and females. You will have sensors applied to parts of your body so we can see on various monitors how you respond to various stimuli. It won’t hurt, although some of your responses may be slightly embarrassing,” John explained.

“Cindy, did you notice if she needed an enema?”

“No, she looked pretty clean when I took her temperature,” Cindy replied. Thank God for my high fiber diet, thought Shelly. An enema would have been unbearable. Poor Shelly didn’t realize what was ahead of her.

At that point the curtain covering the entrance was opened from the outside, and Shelly reflexively moved to cover herself, forgetting she was secured in place on the table. As a pair of hands held the curtain open, a gurney was pushed through the doorway and into the cubicle. The young man pushing the gurney was followed by a young girl, dressed the same way Cindy was…in a student nurse uniform.

Shelly gasped involuntarily as she saw that strapped to the gurney was a young man completely naked and in the same position as she was…on his back, legs in stirrups, spread wide. They placed the gurney parallel to and beside the exam table where Shelly lay, with the man and Shelly facing each other. Their feet were along side each other, so when each looked to their left sides, they could see right into each other’s pelvic areas. The man looked over at Shelly with an embarrassed grin, and Shelly did the same. Shelly couldn’t help but look at the man’s lewdly exposed crotch area, noticing his thick, prominent erection and the gleam of lubricant around his hairy anus beneath his hanging testicles. The man in turn surveyed the scene, looking Shelly up and down from her face, past her breasts, and down to her wet and matted pubic hair surrounding her pussy and anus. His cock throbbed involuntarily.

No introductions were made of the new test subject nor the two new technicians who were now squeezed into the cubicle. All appeared to be busy sorting out electrical leads, clips and plugs, and attaching them to various monitors situated on rolling instrument carts beside the two subjects.

The technicians began working on Shelly and the new man simultaneously. Shelly’s senses were going wild, with her attention alternating between seeing and feeling what was happening to her, and watching with great interest what they were doing to the young man beside her. She watched between her own legs as Cindy snapped on a latex glove and began smearing KY on her fingers. John had a bullet-shaped metal device in his hand, and she could see several colored wires leading from it. Without fanfare, Cindy’s slippery finger slid all the way into her anal opening and began twisting around. Shelly could feel the cool KY up inside her, slowly begin to warm from the effect of Cindy’s finger and her own rectum. As Cindy withdrew her finger and spread her asscheeks wide apart, John inserted the object into her anus, pushing the cold object up with the end of his finger until it completely disappeared into her rectum. Shelly moaned at the invasion of the cold object, and sucked in air as John withdrew his finger, leaving her with a full feeling in her bowels.

“There, Miss Heath. That’s a rectal sensor that’s going to be connected to our monitors. I am now going to insert one into your vagina as well,” John explained.

“B…bu…but what is it going to do to me?” pleaded Shelly.

“Relax, Miss Heath,” John replied. “The sensors being attached to various parts of your body are part of an experiment to test your responses to various stimuli. Also, these monitors are experimental as well, and we want to see if they can capture various physiological data such as sensory neurological responses, galvanic skin response, blood oxygen levels, heartbeat and things like that.”

As John was explaining this to her, she looked over to the young man and saw the same procedure being performed on him. After lubricating his rectum, the student nurse bent down so her eyes were at the level of his anus and pushed the cheeks of his fanny apart with her palms. The technician inserted the metal bullet into his rectum as the student nurse reached over and lifted his testicles up and out of the way. When the probe was inserted, the technician told the student nurse to insert her finger to get the feeling of how far inside the device should normally be placed, explaining that it should be well past the prostate gland in a male. As she was observing this, Shelly felt a tug on the device in her rectum as the technician untangled the wires and plugged them into one monitor with a screen and a printer. Despite her apprehension, Shelly could feel herself getting quite aroused and moist deep within her vagina.

Her attention returned to her own plight as she saw John hand Cindy a similar device and was instructing her how to insert it. Cindy lubricated the sensor with a generous dollop of KY as John placed his fingers on either side of Shelly’s puffy pussy lips, and spread her outer and inner lips wide. Shelly could feel the cold air suck into her female opening as Cindy positioned the tip just inside her vulva.

“Is this right, John?” she asked innocently.

“Yes, Cindy, that’s exactly where you want to be. Now just push it in and guide it in with your fingers all the way. It should rest just about at the cervical opening when seated correctly,” John instructed. Shelly felt the cold probe slide past her pussy lips and up inside her vaginal cavity. As Cindy put her face close to her pussy, she could feel her fingers and the device wiggling around inside.

“Miss Heath, here, is going to be a great subject,” John observed. “She’s already aroused and lubricated on her own. Look at the way her clitoris is standing up already!” Cindy blushed as she looked first at Shelly’s genitalia, then at Shelly herself. Shelly was dying of embarrassment, made worse by the fact that they were talking as if she weren’t even there!

At the same time, the other team was affixing a thin leather collar around the base of the young man’s turgid cock. They had smeared some electrolyte along the inside diameter of the collar before applying it to his organ. Again, the student nurse held the head of his penis steady with one hand and pulled his scrotum down with the other, as the male technician buckled the strap onto his cock. When the first strap was fastened, another strap with electrolyte was wrapped around the man’s scrotum up near the base of his penis, leaving his testicles bunched tightly beneath it and held up off his perineum in the process. Shelly could see his cock and balls waving back and forth as the two team members stretched the colored leads and plugged them into a similar monitoring instrument. The blushing young man stared at the ceiling the whole time, clearly mortified at having his excited cock exposed to a group of clinicians his own age, in addition to another female test subject he didn’t even know.

The student nurses were both tasked with applying the remaining surface sensors to the test subjects. Flat electrodes, similar to those used for EKGs and covered with electrolyte, were applied to their perineums and nipples. Shelly felt Cindy wipe off her perineum with an alcohol swab and blow on her skin to dry it before carefully placing the circular white disc mid-way between her vagina and anus. As for the young man, the young girl first had to shave the hair off the skin of his perineum before applying the electrode. After feeling it to be sure it was smooth, she pressed the disc onto the skin over his prostate, causing a low moan to escape from her captive volunteer. Shelly could clearly see several drops of pre-cum oozing from the tip of his swollen purple cock head.

Shelly presumed that similar discs would be attached to her nipples. Not quite. The technician approached her with two wires with alligator clips at the ends. Each side of the clip was a different color: one gold and one silver. The technician twirled each nipple between his thumb and forefinger, causing them to rise hard and erect, much to Shelly’s embarrassment. When they stood up, he clipped the leads onto each one right at the nipple. The slight squeezing action on the nipple ensured they would stay hard. The clips tugged at her nipples as he ran the leads to the monitor and connected them. The other team was done attaching the nipple electrodes to the young man’s chest at about the same time. What in the world are they going to with us now, Shelly wondered as she surveyed the scene in front of her.

“We’ve calibrated the monitors to each of you to establish personal at-rest baselines,” explained the other technician. “We will now introduce the same stimuli to you both simultaneously and record your reactions in various parts of your bodies. We will compare them later in the laboratory.”

At that, the student nurses produced slim vibrators and turned them on, causing them to buzz madly. Apparently familiar with established protocol, one vibrator was touched to Shelly’s right breast as the other was touched to the young man’s right breast. All the technicians and their young assistants gazed at the monitors, which showed if there was concurrent stimulation in other unrelated areas such as vagina, penis, testicles or anus.

The vibrators were then systematically applied to their right nipples, both earlobes, and finally placed into their mouths. Since the vibrators had been swabbed with an anti-bacterial beforehand, there was little danger of infection when their mouths were penetrated. The girls told the test subjects to open their mouths, whereupon they dutifully inserted the vibrators. After a few seconds of registering responses on their tongues and palates, the vibrators were slowly pushed to the backs of their throats, ultimately causing stimulation of the gag reflex. The girls nonchalantly held their jaws open and steady as they watched the monitors for a few seconds to be sure the responses were registering properly while their subjects convulsed and struggled against their restraints. Finally, the vibrators were withdrawn, leaving both subjects panting heavily and jerking their heads back and forth.

Before Shelly and her male counterpart could recover to protest or ask a question, the girls had moved down to each one’s pubic area. Taking up a position on a low stool between each subject’s splayed legs, they began to touch the vibrators to various points.

The girl working on the young man began with the tip of his highly erect penis, slowly running it down the underside of his smooth circumcised shaft. Shelly could see him flexing his cock wildly, though involuntarily, and a long drop of pre-cum dew squeezed itself out of his narrow slit. The technician told the girl that was good, and to continue with “Phase 2.” She slid the vibrator down to the man’s scrotum, at the same time taking the skin of his hairy sac at the bottom and stretching it downward so the shape of his testicles could be seen on either side. She ran the tip of the vibrator first down the center between his balls, then circled the left, then the right one with her vibrator. The technician was watching the monitor intently and was making notations on the paper strip emanating from the machine.

At the same time, Shelly was having the vibrator applied to her clitoris. The girl had spread her lips wide, and with a slight upward movement pulled back the clitoral hood enough to get the tip right on the swollen pink button. Shelly wiggled and squirmed her hips…she was so sensitive by now, she was afraid she would cum in front of everyone and embarrass herself even more. Mercifully, the vibrator was lifted from her clitoris, but then suddenly she found it penetrating her vagina. Her pussy lips quivered and quaked and the juices flowed out of her so much that the male technician on her team had to wipe her off with a Kleenex during the procedure. It was apparent that the young girl assistant had done this many times before, maybe even to herself, as Shelly observed she was very skilled in applying the vibrator to just the right areas.

Finally, the vibrators were removed and both test subjects collapsed into heaps on their respective tables, staring up at the ceiling. They were both thinking that there couldn’t be much more and they were going to be allowed to leave, when the young man noticed one of the girls applying great globs of KY to the vibrator.

“Wh…what are you going to do now?” he whimpered.

“The final test requires that this stimulator be applied inside your rectum,” the girl said with a combination of shyness and mischief showing on her face. She seemed to be breathing a little harder than before….could she be getting off on what she was putting these two adults through?

Both student nurses resumed their positions on their stools. Looking closely at the shiny, pulsating anuses only inches in front of their eyes, they spread the buttocks and inserted the vibrators. Both subjects gasped out loud as their rear orifices were violated once again. At first, they only pushed them in about an inch, stopping to let the sensations of the anal sphincters register. Then they pushed them in to a depth of about four inches and held them there while they looked back at the monitors. Finally, they slowly withdrew the vibrators, allowing the anal rings to close slowly around the tapered tips.

“We have to redo the prostate reading on your subject,” the other team’s technician told his assistant. “Insert it again, only about an inch, and tilt it so the tip goes upward and contacts his prostate.”

The girl, almost gleefully, pivoted back to face her subject’s crotch, lifted his testicles and deftly inserted the tip of the slim vibrator, carefully watching how far in it went. Then she slowly angled her end downward, forcing the tip inside up toward his testicles. The young man bucked his hips on the table and groaned loudly as she found his prostate, which produced a sly smile from both girls as they exchanged knowing glances. They both were trained in how a boy’s “good spot” reacted to stimulation, and each loved to produce the predictable reaction in their captive subjects whenever possible. Shelly watched in amazement as the young man had his anus penetrated and his ensuing reaction. She would definitely have to remember this lesson for her future sexual encounters!

The readings being finally recorded to the technician’s satisfaction, the vibrator was withdrawn, almost reluctantly, just before the man was about to shoot his load all over himself. Shelly knew how mortified he would be if that happened…yet she was praying it would so she could watch his sweet agony. At least SHE would not be humiliated by ejaculating if she happened to cum.

“John, are we going to reward these two today, since they were so cooperative?” asked Cindy with noticeable anticipation in her voice. “Yeah, can we?” chimed in the second girl with a smile.

“Yes, Doctor Peters has allowed that in the past. We certainly don’t want these two leaving in the condition they’re presently in. The streets wouldn’t be safe,” he said with a smirk.

The technicians removed several of the colored wires from the monitors and plugged them into a different machine with a meter and several rotary controls.

“For being good subjects today, we are going to stimulate you to orgasm electrically. Have you ever experienced that?” he asked, looking at both of them.

Both weakly shook their heads and whispered “No.” They couldn’t stand their sexual tension anymore, and were grateful that they would be allowed to cum. They didn’t even care at that point that each would be watching the other, or that everyone else would be watching as well. They just had to cum!

“I’m going to send a harmless electrical current through your rectum and genitals using a device called a TENS unit. You will at first experience a tingling sensation, then a pulsating feeling as your muscles contract in time with the electrical impulses. I will start out slowly at low intensity, then increase both the intensity and frequency of the pulses until you orgasm. Here we go.”

The girls watched the subjects intently, waiting for their reactions. As the technician slowly adjusted several dials, Shelly could feel a light tingling going up from her anus to the clitoris…then the promised anal contractions began, along with some minor contractions along the upper part of her slit around the clitoris. The young man got the same tingle, except his went from his anal ring up through his prostate to the base of his cock. He bucked his hips at the first pulse, then began gyrating his buttocks on the table the best he could within the confines of the restraining straps. The two girls looked at each other and suppressed a giggle, knowing what was coming next.

As the technician increased the frequency and intensity of the pulses, Shelly began pressing her buttocks down into the table as much as she could manage, adding more pressure to her throbbing clit. She looked over at the young man and wished she could grab his cock right now and do everything in the world to it. She was so horny!

Finally, both subjects began moaning louder and thrashing around. The four techs looked on as first the young man, then Shelly came to explosive orgasms right in front of their eyes, without anything even touching their genitals. The pair came amidst a chorus of grunts, moans and choked sobs, leaving no doubt that they were experiencing very powerful orgasms.

Amazing! It seemed the student nurses never tired of watching this phenomenon, which had been explained by, then later demonstrated by, Dr. Peters. It was decided that they should use this technique as a reward for cooperative subjects so they would be unlikely to spread the word about how truly humiliating their experience had been at the hands of these young student researchers.

Shelly and the young man laid back, covered with a light sheen of perspiration, eyes closed, both out of relief and acute humiliation at having experienced something so personal before a rapt audience.

Once it was clear that both subjects were post-orgasmic, the student nurses busied themselves with detaching all the surface electrodes, then finally gently tugging out the sensors in Shelly’s pussy and rectum, and the young man’s rectum. They swabbed both genital areas clean from all lubricant and body fluids. The girl on the other team had the extra task of cleaning off the young man’s abdomen with a warm washcloth, sopping up his great load of spent semen.

As Shelly was being unstrapped, they began to wheel the young man out of the cubicle, still fastened to his gurney. Shelly and the man looked at each other, and she wasn’t sure, but she could have sworn that he gave her a little wink just before he disappeared out the doorway.

“I hope this experience has not been too unpleasant for you, Miss Heath,” said John. “We do appreciate your participation this afternoon. The data we collected from you will certainly be valuable to our database for future research.”

“N…no, everything was fine. It was the strangest thing I’ve ever done…but…oh, never mind. Can I get dressed and go now?” Shelly asked weakly, not wanting to meet his gaze.

“Yes, get redressed and Cindy will lead you out. Again, thanks for volunteering,” John said as he stuck out his hand to the naked woman. Shelly took his hand and shook it, and to her surprise, she held it for a split second longer than she wanted to. John looked her up and down quickly before telling her, “All right now, you’d better get dressed.”

Shelly turned away quickly and donned her clothing as quickly as she could. Her clothes felt almost weird since she had been naked for so long.

When she was done, Cindy led her to a different vestibule, where she was asked to sign out. Shelly and Cindy exchanged quick good-byes, then Shelly was out the door. She didn’t even look back at the building as she walked down the street in a daze toward her dorm room.

Shelly thought about her experience over the next two weeks, her confusion and embarrassment gradually fueling her masturbatory fantasies, until she finally picked up a leftover flyer at the dorm’s front desk and headed back to the lab.

When she got to the address, she found the doors locked, and the Physio-Lab sign had been removed. She looked around to see if they had moved to another location, and even double-checked the address on the flyer. It sure looked like the same place she had been only a couple of weeks ago.

She crossed the street and sat down on the front steps of an apartment building, just staring at the former location of her Physio-Lab experience. She let her mind wander, recreating her sensual experiences there. She finally crumpled the flyer and threw it into the hedges near the steps and slowly walked back to the dorm. Only one question was on her mind at that point.

Would she ever run into the other young test subject again? And what if she did?