The next day was Saturday and soon after he got up Jack received another call from the clinic. Jack was asked if he would mind coming in to the clinic as soon as was convenient that morning. Since Jack didn't have any plans for the day he quickly agreed. They didn't go into any details about what he would be doing but Jack was sure it would be a very fun and interesting experience for him. Jack quickly dressed, ate a hasty breakfast, and was out the door on the way to the clinic.

After a few short minutes of driving Jack arrived at the office building which housed the clinic. He quickly pulled into a parking space, locked his car, and walked into the office. This was the first time Jack had been called in on a weekend so he was thinking this might be a longer session than he had experienced before.

Jack announced himself to the receptionist and was told he would have to wait a few minutes until they were ready for him. He sat down and picked up a magazine from the table next to his chair to help pass the time. Jack waited for about five minutes until he heard a door in the treatment room area open and a woman briskly walked out toward him down the short corridor.

Jack immediately recognized Mei walking toward him as he dropped the magazine back on the table and stood up. She was wearing a very short, tight mini-dress and as Mei drew closer Jack noticed her nipples pressing through the thin material.

"Welcome back, Jack!" the Asian woman said as she again greeted him enthusiastically. “I’m glad you could come today.”

“Sure, I’m always happy to help here,” Jack replied truthfully.

“I’m sure you are.” The Asian girl replied with a knowing smile. “Please follow me.”

Mei led Jack back to the same room she had just came from and he found himself once again in the same type of treatment room he had been in for his previous visits.

“Please remove your clothes and have a seat on the table,” Mei instructed as she sat down in the rooms only chair. Jack quickly removed his clothes and sat down on the table and waited to see what would happen next. Mei spent a couple of minutes writing on the small desk in front of her and then swiveled her chair around so she was facing Jack.

“Jack, can you stay with us for the entire day today?” Mei asked. “We have several different activities today in which we would like you to participate if you are interested.”

“Sure, I don’t have any plans for today; I can stay for as long as you want me to.” Jack replied.
 
“Great!” Mei exclaimed with a smile. “First we will need you to give us another donation just like the first time you were here. But this time we will be combining that with one of our educational classes so you will be our live model for the class. The class is male sexual function and the students are all young females. Would you like to help us with this, Jack?”

“Sure! It sounds like fun!” Jack replied.

“Thank you for agreeing to participate in our class. You will be providing much needed sperm for one of our clients as well as providing a big help in our education program at the same time. But it is very important during the class to not say anything or do anything other than what you are instructed to do. You’ve been very good with that up to now; will you be able to continue the same way?” Mei asked.

“Sure, I don’t have any problem with that. Just tell me what you need me to do,” Jack replied. “I’m ready whenever you are.” During the short conversation Jack’s penis had awakened and he was already sporting a firm erection. Mei did not fail to notice this as she was explaining what would be happening to Jack.

“Ok, then let’s get started,” Mei said, rising from her chair. “Please come with me.”

Jack got up off the table and followed Mei out the door, his erect cock bobbing in front of him. He followed Mei further down the hall to a room that he had not been in before. Mei opened the door and held it open for Jack to enter and then followed behind him, closing the door behind her.

Inside Jack found a somewhat larger room than the ones he had been in previously but this one still contained the same paper covered examination table as the others. Also inside the room Jack found two more women who he already knew from his previous visits, Karen and Carol. In addition there were five younger girls who Jack assumed to be the students for this session. Karen silently indicated that Jack should take his place on the examination table which he did. Jack could feel the eyes of all the females in the room on his nakedness and especially on his hard, throbbing cock as he walked to the table.

“Our subject has arrived and everything is ready for our session to begin.” Karen began who would be acting as the main instructor in the session. “In this session we will be demonstrating the male sexual function with the help of our volunteer here on the table. As you can see his penis is already fully erect which is to be expected from the situational stimulation he has been receiving. Please come closer so that you can all see clearly what is happening.”

The five girls who were there to learn shyly moved closer to the table. The other two older women, Mei and Carol, gently chivvied them all up until they were standing right next to the table, with Karen on the opposite side. This allowed the five a clear view of Jack, his cock, and anything that might happen with it while at the same time Karen had plenty of room to do whatever she needed to do.

“As you can see our subject’s penis has been circumcised which means the head is fully exposed at all times.  Since he is already well aroused our subject will orgasm pretty quickly so you will need to pay close attention so you don’t miss anything. When he does his semen will be captured for later insemination of one of our other clients.” Karen continued.

“When orgasm occurs I will capture his semen using this special container,” Karen told the group as she picked up and displayed the special glass container the clinic used for capturing semen. “You will notice the open end of the container has a wide flared opening which is large enough to receive the head of the penis when ejaculation occurs.”

Karen reached down and gently took Jacks cock in her right hand. “As you know there are two very sensitive areas of the penis, the head and the frenulum on the underside.” Karen touched both areas of Jack’s cock as she lectured. The assembled girls could see his stiff penis jump with each touch. “You can see at the tip the urethral opening from which the semen is emitted upon ejaculation,” the woman continued, gently squeezing the tip of Jack’s penis to cause the slit to open.

“I will now begin to stimulate our subject’s penis.” Karen continued as she closed the fingers of her right hand around Jacks cock and began to slide her hand up and down. Jack’s cock responded immediately to the added stimulation and Karen felt his cock stiffen even more in her hand. “Since our subject is already well aroused it will not be long before this added stimulation will cause him to reach orgasm. Carol, please hold the container and be ready to catch his semen. I think he will reach orgasm very soon,” Karen said as she handed the container to the black woman.

All this was becoming too much for Jack and he could feel the orgasmic tensing starting in his cock and inside. He was getting ready to cum and it sure felt like it would be a strong one.

“I can tell by the way our subject’s penis is tensing that his orgasm is imminent. Please watch closely and Carol get ready with the container!” Karen warned. Carol brought the open end of the container to the head of Jack’s tensing cock and the watching girls leaned in for a closer view.

Just as soon as the black woman had the container securely over the end of Jack’s cock his orgasm cut lose. The five young girls watched in awe as a strong jet of thick, white semen spurted from the end of Jack’s cock, splashing against the end of the container. For Jack it was one of the strongest orgasms he’d had for a while and each new squirt of his semen into the container brought a new wave of pleasure. Karen’s experienced hand milked his cock expertly, milking out as much sperm from Jack as she could which also just happened to give him the most pleasure.

“You can see our subject’s semen is a sticky, thick white fluid that contains millions of sperm. Normally these would be ejaculated directly into a woman’s vagina but some of our clients prefer artificial insemination. Carol will now leave and carry out that procedure while our subject’s semen is still fresh.” Karen said as Jacks orgasm faded and the last drops of his semen dripped into the container. Carol quickly capped the container and left the room, taking the container of Jack’s semen with her.

The powerful orgasm left Jack spent for the moment and he just collapsed back onto the table. Mei bent down and quickly licked off the last drop of semen that clung to the tip of Jack’s cock. Karen quickly ushered her five young female students out of the room leaving Jack and Mei alone for the moment. Jack was so spent from his orgasm that he actually fell asleep for a time laying there naked on the exam table. Mei worked quietly for a few minutes letting Jack rest to recover so that he would be ready for the next event they had planned for him.

Jack dozed on the table for quite some time until suddenly he was awakened by a soft hand gently shaking him. For a moment Jack was disoriented and couldn't figure out where he was then he opened his eyes and saw Mei just withdrawing her hand from his shoulder.

"Hello, did you have a nice nap?" Mei said with a smile.

“Yes I did,” said Jack.  

“Good,” said Mei. “Are you ready for your next job?”

“Sure! What’s next?” Jack answered.

“If you are rested enough we have a patient here for a natural insemination. It is the same one you inseminated previously; she is here for another session.” Mei told him. “We have found that repeated inseminations by the same donor over a two week period are the most effective method for impregnation.”

Mei’s words sent a nice thrill down to Jack’s cock and the Asian woman could see it responding already. She could still remember vividly the feel of that cock as it slid in and our of her own pussy and she smiled to herself knowing she would be feeling it there again later.

“I’m ready to get started whenever you are,” Jack replied.

“Yes, I can see you are,” Mei replied with a smile. “But remember this patient must remain anonymous and you are not to speak in her presence. Otherwise feel free to enjoy yourself as much as you want to.”

“I remember that from before it won’t be any problem at all,” Jack told her.

“Would you like me to take my panties off before we go in, Jack?” Mei asked.

“Please do, that’s a great idea!” Jack answered.

“Ok, off they come.” Mei said as she slid her thong panties off and down her legs. She stepped out of them and then bent over to pick them up. As she did so her short skirt rode up giving Jack a clear view of her ass and shaved pussy as she did so. “All right let’s go,” Mei said as she set the discarded panties on the small desk and then turned for the door.

As the Asian girl headed for the door Jack got up off the table and followed her, his hard cock bobbing in front of him as he walked. Mei led him deeper down the corridor to another door on the same side. The woman opened and then held the door for Jack as he went inside and then followed him into the room.

Inside Jack found a treatment room of the same type as the others with the same table as the other rooms he had been in up to now. He recognized Karen and Carol standing beside the table upon which was the woman Jack would be inseminating. However unlike the previous session she was in a different position this time. Her head was still covered to hide her identity; but this time the woman was on her hands and knees with her ass up and open. This gave Jack an excellent view of her pussy and ass, both open to him very invitingly.

Karen walked up to Jack and reached down taking his cock in her hand. She stroked his penis a couple of times which sent a thrill of pleasure through Jack. “Jack, I can see you are ready to begin the insemination process so we will get started immediately.” Karen said as she indicated the nude, kneeling woman on the table with the hand that was not holding Jack’s penis. “Our patient has been prepared for insemination and is ready to receive your penis. I will guide your penis into her vaginal opening and after that please feel free to enjoy yourself until you reach orgasm.

When you orgasm please try to ensure all of your semen is deposited completely inside her vagina. You may hold the patient’s hips if you like but please do not speak while you are inseminating her,” Karen instructed as she led Jack to the waiting woman.

Jack was quickly led to the woman on the table that knelt receptively on the table waiting for his cock. Her pussy glistened with the moisture of her arousal for she had already been well prepared for Jack’s penis before he had entered the room. As Karen maneuvered the head of his cock toward the woman’s waiting pussy could see how her inner lips were swollen with arousal and her anus was a cute little star above winking at him. As the head of his cock reached the kneeling woman’s pussy Karen rubbed the head of Jack’s cock around her opening a bit to moisten the tip. Then she set the tip of Jack’s penis right at the other woman’s vaginal opening which Jack took as his signal to start. He grasped the kneeling woman’s hips and slowly pushed forward.

Jack sighed in pleasure as his hard penis slowly sank deep into the woman’s vagina and he could faintly hear the woman make a similar noise. When his cock was completely seated in the woman’s pussy Jack slowly withdrew until just the head of his penis was inside her. Then Jack pushed inward again a little faster this time until his hips lightly slapped against the kneeling woman’s buttocks. Jack worked his cock in and out a few more times until the woman’s vagina had completely opened for his penis. As he did so Carol at the side of the table reached under the woman on the table and started to play with her nipples.

As Jack began to fuck the kneeling woman in earnest she began moving her ass to meet each inward thrust of his cock into her pussy. Soon the sound of Jack’s hips slapping against the woman’s ass as he fucked her deep and hard filled the room and Jack wasn’t going to last long until he reached orgasm and filled the woman with his sperm. The view of the kneeling woman’s ass and her pussy lips clinging to his deep and hard thrusting cock added to the pleasure he was feeling from the inside of her vagina. Jack could feel the final sweetly pleasant tensing of his cock and prostate gland just before orgasm.

As Jack was pushing his cock into the woman’s pussy the final bit of sensation pushed him over the edge and he began to cum in the woman. A thick jet of semen shot out of Jack’s cock and splashed the silky walls of the woman’s pussy. Jack’s movements quickly grew uncoordinated as the strong pleasure of shooting his sperm into the kneeling woman filled him. The woman gave a muffled moan as she felt Jack cumming in her. Jack kept his cock deep inside her as he inseminated her until finally the force of his orgasm was spent and he slowly pulled his cock out of the kneeling woman.

Now that Jack was finished Karen gently pushed Jack a couple of feet back from the table. Mei quickly slid in front of Jack, knelt down, and took his shrinking cock in her mouth. The Asian woman licked off every trace of remaining semen from Jack’s cock and then stood up again. Then Mei took Jack’s hand and quickly and quietly led him out of the room and back to the room where he had been previously.

“Jack, why don’t you take a rest for a few minutes? We have a little time before the next thing we would like you to do for us,” Mei suggested as they entered the room. Jack almost staggered to the table as a sudden wave of fatigue swept over him and suddenly the paper-covered treatment table looked very inviting. He quickly climbed up upon it and then collapsed as Mei sat down in front of the small desk. Almost as soon as he came to rest on the padded table Jack fell asleep.

Jack slept for about an hour and during that time Mei and several other women came in and out of the room.  Jack was allowed to rest for a time to recover his energy and become ready for the next thing they had for him to do that day. As the various women came in and out of the room they took in and enjoyed the sight of Jack laying there naked on the table as he slept.

Jack came back to awareness slowly and it took him a couple of minutes to remember where he was. Finally he realized he was still at the clinic and he opened his eyes and looked around the room. He noticed that Mei was no longer in the room but instead Karen was sitting at the small desk against the wall. After a couple of minutes Karen glanced over at Jack and noticed he was awake.

“Hi Jack; are you ready to get back to work?” Karen asked him with a smile. Somehow referring to what Jack had been doing as “work” made it more exciting.

“Sure! What do you want me to do next?” Jack answered.

“We have another class scheduled and this class requires a live demonstration of sexual intercourse. We would like you to be the male participant in this demonstration and I will be both the instructor and the female participant. Do you want to help us with this?” Karen asked.

Jack quickly realized this would mean he would shortly be fucking Karen. “Sure! I would be happy to help,” Jack replied with a smile.

“Great! I would like you to just like still and let me do all the work and please do not say anything during the class it will distract the students. Just concentrate on enjoying yourself and let everything come naturally. At the end I want you to orgasm and ejaculate inside me.”

“No problem, I’m ready when you are,” Jack replied. Karen smiled as she saw his cock harden to prove it.

“OK, just wait her while I got get the others and then we can get started,” Karen said as she stood up. She quickly walked to the door and left, leaving Jack alone on the table. He lay there quietly for about two minutes and then the door to his room opened again. As the door opened Jack was reminded he was laying there naked on the table with his hard cock rampant and easily visible.

When the door was fully open Karen walked back inside the room followed by the same five girls who had watched Jack earlier in the day and then Mei and Carol. Jack watched silently as the women moved up to the table where he was laying and his hard cock jumped as he realized every girl now had a close up view.

“For this session we will be giving a live demonstration of sexual intercourse.” Karen began when all the women were in position around the table. “Jack here will have the male role and I will be the female. Mei and Carol will assist as needed. In order to continue I will need to remove my clothes.”

Karen quickly unbuttoned her blouse and handed it to Carol who set it aside before unzipping her skirt and letting it fall to the floor. Since she seldom wore underwear this left Karen nude and ready to continue. She stepped out of her skirt and turned back to the table while Carol picked up her discarded skirt and set it aside.

“To continue, I will be demonstrating today human sexual intercourse. During this session you will be able to see in practice what you have learned about in previous sessions.” Karen continued as she turned back to the table where Jack lay. “For this demonstration I will be using the female superior position which as you know has the male on the bottom and the female above him. We are using this position today because it will allow you to easily see every detail of the penis entering my vagina and it’s movement inside me.”

Karen fell silent for a moment as she started climbing up on the table where Jack lay. She swung one leg over his body until she was straddling him with Jack’s cock head a couple of inches away from her pussy with one leg on either side of his body. The five student girls could clearly see the man’s erect penis and Karen’s anus and vaginal opening and since Karen was completely shaved they could see every detail of her sex. Karen’s position caused her pussy to open which exposed everything to the student’s view.

“I will now begin sexual intercourse, Mei please guide his penis so that it enters my vagina correctly,” Karen instructed as she slowly slid her body back toward the waiting cock. Mei reached down and grasped Jack’s penis in her hand and guided it into the other woman’s waiting vaginal opening.

The student girls watched in fascination as the head of Jack’s cock spread the opening on Karen’s pussy and then slowly slid inside. When the head was fully inside her pussy Karen stopped for a few seconds and then pushed back a little more, driving Jack’s cock a little deeper into her pussy. The woman slowly impaled herself on Jack’s penis until it was fully inside her vagina. The five girls watching could see every detail of how Jack’s penis filled Karen’s vagina.

“As you can see Jack’s penis is now fully inside my vagina. Even though his penis appears quite large when erect it will still fit inside me quite easily. The feeling of it inside me is quite delightful,” Karen said as she held herself still while fully impaled upon Jack’s cock.

“Now that the penetration of my vagina is complete I will begin the in and out movements of sexual intercourse. Since I have the most freedom of movement I will move my hips and body so that Jack’s penis is moved in and out of my vaginal opening,” Karen continued as she began to move on Jack’s cock. The five girls watched fascinated as the woman’s hip and body movements caused Jack’s cock to move inside her pussy. For Jack Karen’s every word and movement sent a new thrill of pleasure through his cock and into his body.

Karen fell silent as she started getting into the work of sexual intercourse with Jack and the five girls were just left to watch. Karen quickly found a very pleasant rhythm to ride Jack’s cock and was soon lost in the wonderful feeling of Jack’s cock moving inside her pussy. The five young girls watched entranced as the older woman fucked herself on Jack’s cock. They all stared raptly at the way Karen’s movements caused Jack’s cock to first withdraw almost completely and then drive deep into her pussy. Occasionally Karen would vary her movements, changing from and up and down movement to a front to back movement which allowed her to rub her sensitive clitoris on Jack’s body.

Since Jack had already had two orgasms so far that day he was able to enjoy the experience for quite some time without any danger of cumming too soon. Jack resisted the urge to push up into the woman riding his cock, he did his best to let her move and just enjoy the feel of her on this cock and the view of her face and body. And the 5 young girls and the other two older women were still watching every detail which gave Jack an added pleasure.

“This is feeling really good!” Karen said, her words broken between moves of her body. Her breathing was very rapid now and she was fucking Jack as fast as she could. The woman could feel her orgasm rapidly approaching and in truth she really got off sexually on this exhibinistic instruction. “It’s coming now! Ohhh!” the woman exclaimed as her orgasm blossomed from her pussy throughout her body.

The five young girls watched in fascination as Karen squirmed in ecstasy on top of Jack. Jack when he had sensed the woman was about to cum abandoned all efforts to hold back his own orgasm and let himself enjoy fully what was happening. As Karen’s orgasm started to fade Jack launched into his own orgasmic pleasure.

“The male has now reached orgasm and he is ejaculating inside my vagina,” Karen said, panting from her exertion as she felt Jack begin to cum inside her. Jets of thick, white, warm semen shot out of Jack’s cock and splashed the walls of the woman’s pussy. Karen relished the feel of the warm sperm shooting into her unprotected vaginal passage. Like all the women who worked at the clinic Karen had a strong fetish for unprotected vaginal sex. The feel of Jack’s sperm shooting into her pussy quickly triggered another orgasm for the woman and the 5 girls watched wide eyed as her body squirmed and bucked again in orgasmic ecstasy.

Karen finally collapsed exhausted on top of Jack’s body, his cock still inside her but softening slowly. The five girls started quietly at the connection of male and female sex organs until finally Jack’s penis softened enough to slip out of the woman’s vaginal passage. As the head of Jack’s cock slipped out of Karen’s pussy a thick blob of their mixed fluids followed and dripped down onto Jack’s testicles. With this Mei started to usher the 5 young girls out of the room and Carol moved in closer to the table.

The black woman quickly climbed up onto the table and moved her head up behind Karen’s bottom. Carol first started to lick up the fluids that were dripping out of Karen’s pussy, even pushing her tongue inside the other woman’s vagina to get more. Then she took Jack’s penis and licked away the sheen of sexual fluids that coated it. It was only a few minutes until she had both Jack and Karen’s genitals clean.

After a moment longer Karen stirred and smiled at Jack then lifted herself up and then she and Carol were off the table and immediately left the room without a word. Jack was left lying naked on the table and he soon fell asleep once again.