Jack decided he'd like to try turning into a girl. He'd always been kinda jealous of how carefree the cheerleaders at his school seemed, and felt like it'd be fun to be one. He found the gender option, clicked the button that would invert his gender, and set it so it would affect reality and no one would know about the change except him. Before initiating the change, he locked his door and undressed, wanting to see his body change.
Once he started the change, he stood in front of his closet mirror and felt a tingling sensation swept over him as his body began reshaping itself. He shrank by about 5 or 6 inches and dropped 60 pounds as his proportions feminized, and within seconds he had a more petite, curvy figure, more lithe muscles and smaller hands and feet. His skin softened and smoothed all over, most of his body hair vanishing to give him a distinctly more girlish look. He felt a shiver brush across his features as his face changed, and before he knew it he had a narrower neck, softer cheeks, puffier lips and longer hair.
An indescribable feeling of tension and arousal now washed through him, and he realised his genitalia was about to change from male to female. And as it did, things seemed to shift around in his head. His nipples became sensitive and erect, and they expanded to be larger and puffier than normal. He panted and saw soft mounds of flesh growing under them as he formed large breasts, about C or D-cup if he had to guess. As they swelled up he imagined having them played with, and having his nipples rubbed and pinched and licked and sucked on. The desires he felt seemed so alien to his old self, but so befitting of her new self.
Soon the last change took effect and he felt an intense sensation in his crotch. He saw his penis slowly shrink away, surprised not to feel any discomfort but only pleasure. His testicles moved up inside him, and he felt his body be castrated as they turned into ovaries and the mound of his scrotum tucked inwards. In response, she adopted the perception of herself as female in her head. As his penis finished receding into her clitoris and her scrotum split open into vaginal lips, she felt fully feminized.
Soon Jackie came down from the high of her transformation, and looked in her closet to see a cheerleader outfit. She smiled. She had a feeling she was gonna like this new life...