Suddenly and without warning, Eric grabbed Dr. Kevin's head and forced him to swallow the entire length of his cock. He then began slowly thrusting, until another gallon of semen came rocketing out of his uretha and straight down the waiting doctor's throat.
And so began a long and arduous process. Eric kept thrusting and deepthroating the doctor, who eventually gave in and let his body go limp as Eric shot river after river of his seed, which was steadily becoming thicker until it had the same consistency as fermented cream. Each time Eric came, another change occurred. First, dense hair continued to cover his body until only the palms of his hands and the soles of his feet were still smooth. His face then started to fold in on itself, giving him a flatter nose, broader forehead, and more ape-like mouth. He stood up, feeling layers upon layers of raw muscle packing on to his once scrawny frame, giving him powerful abs and arms so thick they looked like could uproot trees.
Eric couldn't help but grin, his sharp canines protruding from his mouth. He knew that the more he climaxed, the faster his body would change. He didn't care. He felt too good to stop cumming.
By now, his balls were the size of bowling balls and covered in fur, while his cock now had its own foreskin that peeled back to reveal juicy veins running along the length of his penis.
Eventually, Eric felt empty. Even sasquatches only had so much semen in their balls. He could no longer speak human language, but his intellect remained at the same level. He grunted in pleasure and pulled the doctor away from his softening cock.
Except the doctor wasn't there any more. Instead, a female Sasquatch with heaving breasts stood before him. She grunted something that Eric's advanced brain was able to translate as demanding that he mate with her. He grunted back that he didn't have any seed left.
To his surprise, the former doctor simply smirked, which was only possible because her face still looked somewhat human. She walked over to the table and picked up some kind of vial. She grunted for you to drink it.
You could feel your testes going into overdrive as they made gallons of fresh cum. The doctor grabbed your limp dick and began to rub it with the smooth skin of her palms. You wrapped your ape arms around her and let your tongue mingle with hers as your prick slowly came back to full strength...