Sean never thought his time in special forces boot camp would be quite like this. Everything started off as he expected, but he never thought he would be participating in a special medical research program. After doing well on his physical fitness tests and some endurance testing, he got an invite to this program. The invite shocked him by suggesting that he donate his testicles, but he was curious about the robotic testicles he would receive. He asked his sergeant about what it all meant, but the sarge just smiled and said several of the soldiers on base had participated including himself. The procedure was a little strange, but on the most part intensely pleasurable, and afterwards the robotic balls made for much better sex and you ended up with a bigger dick at the end of the day. Some guys also had kids later with the stored sperm, and Sean figured he had nothing to loose.
As sean watched the ceiling tiles go by as he was wheeled to the treatment room on his gurney, he went over in his mind what the docs had told him. He would be connected to the research equipment where first his sperm would be collected for his future use. Once they had collected all he could produce, the doctors would conduct their experiment and have him produce some special engineered sperm, but that would burn out his testicles. The docs would then give him robotic testicles that would do a much better job of maintaining his testosterone levels - it would be like he was on a safe form of steroids. The docs had examined him throughly. Sean was a muscular man with unusally smooth skin, large nipples, a nice cock and great set of balls. He was in perfect shape, and had dark blonde hair all over his body. After the briefings Sean had been in the hospital for a few days as he was switched to IV nutrition, given drugs that made him super horny, subjected to strange injections into each of his nipples, and had all of his body hair shaved by a muscular nurse. This morning he was given a very thorough enema (he'd be in treatment for almost 36 hours), then stripped naked and restrained on this gurney. Only a thin sheet was covering his muscular (and embarrassingly) erect body as he was taken to a room in a closed-off wing of the facility.
Sean was wheeled into the center of the treatment room. Once his gurney locked in place, the nurse removed the sheet and revealed Sean's smooth muscular form. The nurse wasted no time in checking the restraints, then proceeded to methodically connect Sean to the treatment room's equipment. First the nurse connected thin, clear plastic tubes from a milking device to Sean's firm and thick nipples. The nurse admired the dark skin of Sean's wide aureolas as the suction drew each thick nipple slightly up from the thickly muscled chest. The nurse then proceeded to connect tens muscle-control pads to all of Sean's major muscle groups. The nurse disconnected the IV bag, and replaced it with a line from the treatment room equipment. The nurse also fitted a gas mask onto Sean's face, which immediately began to administer a light mixture of nitrous gasses designed to sedate Sean and stimulate blood-flow throughout his body.
Having finished with the rest of Sean, the nurse moved to Sean's midsection. He first sterilized Sean's cock, balls and perineum. Then the nurse moved a tray over containing two long needles connected to tubes leading to the rooms equipment. The nurse slowly but firmly inserted the needles behind Sean's balls deep up into Sean's body. The needles were sized so that once they were fully inserted the tips would sit in the middle of Sean's prostate where they could induce contractions in the organ and deliver nutrient fluids directly to the gland.
The nurse then placed Sean's balls in what looked like a Plexiglas ball stretcher. The stretcher served to keep the prostate needles in place, keep Sean's legs spread, and keep his testicles in position for the procedures to come. The stretcher also had needles similar to the prostate needles in it, and the nurse slowly impaled each of Sean's nuts with the cold steel. This caused Sean to gasp in pain but the drugs quickly calmed him down.
Finally the nurse turned to Sean's cock. The nurse brought over a long dual catheter designed to collect Sean's urine and also directly collect each of Sean's ejaculations. The nurse lubed the tip of Sean's penis, then slowly slid the catheter deep into Sean's body. When the catheter reached Sean's bladder, the nurse inflated the retention balloon and checked the flow of urine. The nurse retrieved two syringes of a growth hormone solution, and proceeded to make 4 injections down both sides of Sean's cock. Now fully medicated, the cock was ready for the external suction device, which the nurse fitted around the base of the dick. As soon as the suction device was in place, the treatment system came to live and began to stimulate Sean's body.
The nurse stepped back and watched as the machines took over the young muscular form tied down in the center of the room. Sean's breathing immediately deepened as electrical signals began to flow through his body. The nurse noticed how Sean's nipples were getting erect, the alveolar tissue became tense, and small rivulets of sweat broke out all over the pale muscular body. Sean's level of sexual tension began to build, and the nurse grinned as Sean's toes began to curl and a moan escaped Sean's masked mouth.
The nurse left the treatment room just as Sean reached his first orgasm. After the injections over the last few days his body was primed for sex, and the electrodes had no trouble coaxing Sean's muscular body to an intense climax. The climax was fun, but a little strange as Sean could feel himself being pushed over the edge by the needles in his balls and prostate, he could almost feel fluids entering his balls and prostate from the needles, and of course it was weird to cum and have the spunk sucked out from inside his dick. Strangeness aside, it was one of the best orgasm Sean had ever experienced. The qc system registered good sperm and after a few minutes of rest, the cycle began again. Over the next 10 hours the system continued to harvest sperm from Sean with enough total collection to allow Sean to father a small army.
Sean was delirious from the pleasure even as the qc system indicated that the last of his sperm had been milked out by the electrodes and fluids being fed into his glands and prostate. This triggered a signal to the doctors that it was time for the implantation, and triggered a cleaning sequence to ensure no sperm remained in Sean's body. As the staff made their way back to Sean's treatment room, Sean's prostate and balls were flooded with the saline nutrient fluid. If Sean didn't have the sperm catheter in place, it would have looked like his cock was leaking a continuous flow of precum. The cleansing flow lasted for 10 minutes during which Sean felt almost like he was cumming.
The nurse came back into the room, but this time a surgeon followed him in, carrying a sealed metal tube. The men quickly moved to Sean's midsection, the nurse efficiently sterilizing Sean's scrotum while the surgeon moved his equipment into place. Sean was still panting from the feelings of precum-orgasm as the surgeon quickly made two incisions into Sean's scrotum, then opened the tube. The nurse had seen this procedure done many times before, but still felt a slight wave of nausea as the surgeon took two small globs of dark green alien tissue and placed them inside the healthy pink skin of Sean's scrotum. The treated men all seemed very happy with their replacement testicles, but the procedure still bothered the nurse. Even so, the surgeon was done within a minute and quickly put a temporary stitch in place. There was no going back for Sean's balls now.
Sean's mind was buried so deep in a state of arousal that he barely noticed anything had been done to him. He was still sweating profusely and his body was barely coming down from the orgasmic plateau as the surgeon and the OR nurse exited the treatment room, and locked the door behind them. In the vestibule they passed the treatment doctor, who began activating machines that would fuse the alien tissue to Sean's nuts.
In the treatment room Sean looked down in almost horror at what had been done to his body. He was sedated, but still could recognize that a series of heavy duty cables and tubes were hooked deeply into his cock and balls, not to mention the leads all over his body and the needle-suction devices that were (was it milking?) his chest. Suddenly Sean realized the machines and cables were coming to life, but unlike the last set of treatments this felt very different.
The first thing Sean noticed was a vague sense of warmth as the radiotherapy machine engaged. The machine put out infrared and ultraviolet radiation to keep Sean's lower body sterile and warm, but sent powerful bursts of gamma waves through Sean's testicles. These waves quickly broke down certain cell membranes, setting the conditions for the next phase. Sean couldn't feel the radiation, but he could feel a vague, almost boiling sensation as the radiation did its job. The machine finished it's sequence then switched to monitoring mode to guide what happened next.
Next the electrodes inserted into Sean's balls engaged. Unlike the pleasurable orgasmic sensations during the harvesting of the last of Sean's normal sperm, Sean felt like his balls were being ripped apart by the pulses, and he could feel his whole body spasm in pain. The pulses were causing the alien tissue to infiltrate his testicles, ripping apart the normal tissue as his balls were permeated with the foreign cells. The doctor carefully monitored the extent of tissue penetration, and just as Sean's testicles were fully permeated, he switched the electrodes to fusion mode. Sean felt the ripping sensation immediately stop, but it was replaced by a prickling burning wave almost like his nuts were being boiled in his sack. This went on for a full 30 minutes, all the while alien DNA was mixing with Sean's own in his testicular cells. The doc then ramped up the doses of drugs into Sean's body to the maximum levels tolerable even by a young man - no one could take that level for more than 24 hours without serious side effects.
The burning feeling slowly subsided, and after only a few minutes of rest the orgasm inducing electrode program fired up. Sean loved the sensations just as before, but these were somehow more intense. The signals flowing into his nuts and cock quickly ramped up his arousal level, and the tens pads all over his body started his muscles flexing again. Within 15 minutes he had his first orgasm, and just as before his ejaculate was pleasurably sucked directly from the base of his cock into the collection and quality monitoring system. The nipple pumps came back to life, and just as his first batch of sperm passed qc, his nips began to dribble out a new batch of lactate. Sean was quickly lost in waves of intense pleasure as he began his term of service as a human sperm machine.
After 20 hours of production, the sperm quality monitoring system alarm went off - even though Sean had a strong body and a great set of balls, they could only take so much of the forced fusion with the alien tissue. Once they reached their limit, the tissue quickly began to degrade. Sean had almost set a record for production, but it was good his balls were starting to give out. The treatment doctor had kept Sean's body tweaked at a very high level of exertion, and in a few more hours the production cycle would need to be stopped to prevent damaging Sean permanently.
The alarm triggered an immediate call to the surgeon and the OR nurse. The electronic induction equipment and radiotherapy devices were disengaged, and the two men entered the treatment room. The room was still dim, and the sight of Sean's sweating, exhausted naked body splayed out under the machines was an image they would both remember. The men wasted no time in swinging back the radiotherapy, releasing the testicle harness, disengaging the needles from Sean's burnt out testicles, and quickly reentered Sean's scrotum with the robotic probe.
The fusion with the alien tissue had totally destroyed Sean's testicles. If it hadn't been for the sedatives, the pain would have overcome the feelings of orgasmic pleasure and Sean would have gone into shock. Wasting no time, the surgeon quickly removed the alien-human tissue that once was Sean's testicles. The OR nurse then disposed of the spent greenish organs in a biohazard bag.
The OR nurse rolled over a sterile tray containing the robotic testicles selected for Sean. The orbs were 60% larger than his old testicles, and were mostly smooth in appearance, but had a slightly rough extension around the back. Once implanted, no-one would be able to tell that Sean had synthetic organs in his sack. The orbs contained their own power source, and would recharge from Sean's bloodstream, and be able to absorb enough nutrients to produce high levels of testosterone and growth hormones. The levels would result in Sean maintaining a youthful, muscular body for years longer than would otherwise be possible.
The surgeon gently picked up one of the orbs and slid it into Sean's empty scrotum. Using the remote probe, he gently grafted the cords and blood vessels that formerly fed Sean's left testicle onto the metal sphere. The surgeon then repeated the same procedure with the right testicle. With no further procedures required, the surgeon removed the probe and stitched up the incision. The OR nurse then proceeded to assist the surgeon in removing the various tubes and probes from Sean's body. They gently withdrew the prostate irrigation and stimulation needles, the chest pumping equipment, the catheter collection system and the rectal probe. Sean's body still looked good, but clearly was a bit beat up from the experience. The surgeon pulled a light sheet over the young man's naked form. Finally the surgeon left the room, and the OR nurse called the regular nursing staff to wheel Sean's spent and modified body off to recovery.
Sean slowly started to come to in a quiet recovery room. As he slowly awoke, he felt vaguely sore all over, but had enough sedatives coursing through his veins to prevent any serious pain. He was no longer had an iv, and as he looked down at his body he was happy to see that there were no wires, probes, leads or tubes connected to any part of him. Cautiously he started to flex his sore muscles and stretch out a bit. It really didn't feel like anything worse than waking up after a long night out.
A male nurse monitoring the rooms came in to check up on sean, and noticed that he was awake. "Ok Sean, time to get up and check out your new robotic balls."
The nurse helped Sean out of bed and over to a mirror. The nurse lifted up Sean's gown, revealing a lengthened, thickened cock resting gently on a much fuller scrotum than before. Sean could see faint scars on either side of his sack, but already the stitches had begun to dissolve and disappear.
"Wow - I had no idea I'd get bigger than before!" said Sean as he gently fondled himself.
The nurse let out a chuckle "Most of our patients say that. The treatment program is a bit rough, but your new balls will really help you out. They'll keep your testosterone at the perfect level for muscular development, and no more worries about getting girls pregnant."
Sean smiled, but all he could think about is how the girls were going to enjoy his new equipment. And they did!