Jeff thought back to all the weird porn he had seen browsing through adult image forums. Of humans twisted and corrupted into strange new shapes and minds addled with thoughts of nothing but sex. He supposed such a life would be easier, if he were to turn into a strange beast, with a passing semblance to former humanity. No responsibilities, no desire other than to eat and fuck. He could see it now. He knew exactly what he wanted for his strange new reality, and he wasted no time putting his plans into motion. Humans would become simple creatures that constantly desired sex, and would be designed to do little else except eat and fuck.
He told the Chronivac exactly what shape humanity should take from now on. First, they should be quadrupedal, designed to walk around on all fours. This would mean the spine, arms, legs, and neck would have to realign accordingly. He decided to leave the hands and feet alone, as it would be a good idea for the human hand to operate normally since it might make sex more fun.
Next, humans needed to be thicker all over. They needed a thicker neck, and a thicker body. Women would need larger breasts and buttocks overall, and men would need larger dicks and balls. The anus would thicken out too, becoming a thick, sensitive donut. The face would be a little bit longer too, to be perfect for sucking naughty bits with. The lips needed to be much thicker and more sensitive too, like a perfect skin colored donut of pillowy fat. Their hair would grow out thicker, fuller, and softer too.
Then, Jeff went to work on the mental stuff. First, humans would constantly, instinctively desire sex most importantly. An endless desire to fuck that not even constantly fucking can ever satisfy. Humans would always have the energy to fuck if they didn’t also need to eat or sleep, but even in their sleep they would constantly have sexual thoughts and instincts and desire. It didn’t matter much who they had sex with as long as they were having sex.
Humans would communicate with each other through near field telepathy, which would be a benefit because they could no longer talk but instead only be able to moan. Moans would always sound sexual too, which would make one crave sex even more. They could only communicate telepathically with members of their own species, however.
Last, a few housekeeping changes and then he was ready to launch the world into sexual corruption. He added cum and breast milk to the human diet, and replaced the production of urine and feces with more cum and breast milk. He left farting alone, and gave humans the power to learn about each other by sniffing and sucking on each other’s anuses. Finally, humans would be subservient to the new dominant species of the world, which he decided would be humanoid mammal people like cats and dogs and rabbits and bears and foxes and kangaroos and such that weren’t ungulate or monotremes.
With Jeff’s design put in place, he pressed the start button and waited for the intercourse he was about to never get enough of.