Simon didn't really notice that the changes were happening, until his hair went past his shoulders. At the thought of this, he became excited, both mentally and sexually. Having now a raging boner, he stripped his clothes off in the middle of his room. That's when the real changes started happening.
His body first changed structure, giving Simon immense pain. His bones realigned, making him more feminine, as his shoulders scrunched up, and his waist was squeezed. His hips flared out, making childbirth easier, as his straightened and was bent backwards, giving his spine a more cat like shape.
His legs grew long, skinny, and elegant, yet firm and strong. His feet became thin and dainty, and his arm slendered, giving a slightly bookwormish feel, as if she spent many nights studying. Her hands were graceful, like an artist of any kind. His face became littered with a few spots of freckles, not enough to enhance her new beauty, in fact, it was enhanced. Freckles down to his neck, and reached the top of his chest, before stopping. His eyes turned a bright blue, and his hair a fiery red. Now came the parts that counted. His butt expanded, making it plump, and heart shaped. Her breasts then formed, pushing out of her chest, as she started panting, growing more with each breath. The new sensations grew along with them, and precum started leaking out his cock, as pleasure kept attacking her, making more and more flow out of her cock. She sat down, so that it was easier. Being a virgin, the sensations were brand new, along with never actually cumming before. The more he stroking it, the more it shrunk, until, at the last inch of his manhood, and enourmous amount was shot out, possible gallons, which seemed to float in the air, before a jar materialized around it. Huh, that's convenient, Simon thought, before his dick and balls. we're sucked in, transforming into a fully functioning vagina. He was still fingering it, and got to the point of pleasure, in which he stuck his whole hand inside and started pushing in and out, having orgasm after orgasm from the pleasure.
He then promptly passes out, in a puddle of girl cum, next to a jar filled with her boy cum.
The Next day...