Ty pulled off his pants, and lay on his bed admiring his toned, naked form. As he did, a thought formed in his head: he could change his body into anything. Something that fascinated him was women's bodies: it wasn't just a desire to have sex with a woman, but to be a woman, to know how it feels. Just the thought of it, that he could make it happen right now, excited him.
He looked at himself, took a deep breath and wished. "I wish my body would change sex, with my knowledge and mind adapting to fit but everything else about me remaining the same." As he did, he felt a tingling all over his body, particularly in his chest and his crotch. He felt like he was becoming softer all over- his muscles thinned and his pecs withered into a petite, toned stomach. His hips rounded and his waist thinned, his arms and legs looking more shapely. His face resculpted itself into a beautiful feminine shape and his voice becoming higher pitched as his larynx shrank.
Finally, the femininity taking hold of his body turned to his nipples and his penis. His nipples enlarged and turned erect, and his fingers were quick to play with them, the flesh around them rising as they were rubbed, Ty's hands and aroused mind urging his body to form breasts. Playing with his new-formed tender flesh was causing him to moan excitedly.
In his crotch, he felt an unfamiliar sensation: emptiness. He felt like he wanted his body to be filled, and two fingers began rubbing his perineum longingly, the back of his hand rubbing along his pulsing but still flaccid cock. His body responded to this touch by causing his testicles to move up inside him, and the flesh that had fused while he was still in the womb split into moist lips, her fingers slipping inside herself and causing her to moan. What was left of her penis was receding into her new clitoral hood, but she hardly noticed thanks to being preoccupied with fingering and groping her newly formed body. Eventually she came hard, her body clenching around her fingers, her nipples and clitoris tingling with pleasure.