...a male about to be milked for his semen. A second later, Ty found himself in a pen with a pretty girl about his age. Both of them were naked and their intelligence had been reduced, so their minds went to only one thing: mating.
Ty got atop the young woman, kissed her and rubbed his cock along her slit, both of them breathing in in anticipation. He pushed inside her and they groaned eagerly, and Ty soon began to thrust his hips in and out of her, slowly at first and steadily picking up speed. He saw her breasts bounce and cupped them to hold them steady, making her face contort in pleasure at the touch, and his balls slapped at her as he fucked her faster and faster. He couldn't believe what they were about to do- he would cum in her and get her pregnant, and soon the aliens would make him like her. The knowledge of what was to come turned him on more, and he hastened his motions to try to bring it about faster. Her inner walls clenched around him as she reached her orgasm, and pushed him to his own peak, making him pant as he released thick loads of his cum inside her.
Once they had both finished cumming, alien farmers came in and pulled Ty's lover away from him, leading her away to mature the offspring she would bear. Even as Ty's semen dripped down her legs, the sperm that had been shot inside her were now working their way towards her waiting egg and fertilizing it, getting her pregnant.
The alien farmer who stayed with Ty set up a screen in front of him and a tube around his penis. It turned them on, and Ty watched an endless series of videos of humans mating, arousing him intensely, while the tube sucked on his shaft in a manner perfectly imitating the vagina he had just fertilized. He barely even noticed his attraction gradually shifting until he found the men's bodies more attractive than the women's. At last he came, long and hard, the tube sucking every drop of semen from his body. He saw an almost endless stream of white fluid flow from him, realizing his masculinity was getting sucked away before his eyes.
At last Ty's orgasm subsided, and as the tube was withdrawn, the alien farmer lay him back and shone a bright ray across his body.