At midnight, Bobby awoke with a start. All of a sudden he felt deeply weird- his pajamas felt uncomfortable against his skin. After a moment of hesitation, he checked to make sure his door was locked and undressed. Even in just his underwear he felt a kind of itching irritation, so he decided to remove them too and just try to sleep naked.
Just as he was about to climb back into bed, he noticed his reflection in the bedroom's mirror and gasped. He looked so different all of a sudden. His muscles had shrunken, and his figure looked more small and curvy. Even his face seemed to have changed a little, his lips were puffier and his neck seemed narrower. He kinda looked more... girlish? No, he told himself, this must just be a dream.
A moment later, he felt sensations that were so real they couldn't be mistaken for dreaming. His nipples became super sensitive and he saw them expand before his eyes, strange but deeply arousing fantasies of other people playing with them filling his head. He breathed heavily and felt a swelling in his chest as large soft mounds sprouted from it, until what they had formed was unmistakable. Breasts.
By now, only one part of Bobby still looked like it belonged to a boy, and he felt a flash of fear as he looked down to it, feeling it twitch as the odd sensations flooded through it. Fear turned to arousal as it was changed beyond recognition. He saw his penis start to shrink back into him, but as it shrank it only grew more and more sensitive, and the addling effect it had on his brain steadily dissipated. Beneath it, his testicles tugged up from the scrotum and started to reshape as they moved inside the body, which had a dramatic mental impact. All of a sudden, He was She.
Roberta, as she now thought of herself, watched and felt the changes continue with more comfort after that. They felt like they had more reason to them, and her mind stopped objecting to them. In fact, as her clitoris formed from what had been his penis and a vagina opened out between her legs, she felt contented with her new sex.
After she came down from the aftershocks of her transformation, she got into bed, and to her relief actually slept well.