...change his gender. I remembered one of the girls in his class talking to me once, and she mentioned he was a real jerk to girls. He'd be rude to them if he thought they were dumb and harass them if he thought they were hot, and the teachers did nothing to stop it. I figured it'd be a lot of fun to teach him a lesson, the hard way.
Just like when I had changed Dustin the first time, I focused on the wish- I wished he knew what it was like to be a girl. And as I watched, his body started to change. His skin smoothed and he shrank down all over even further, and for a moment a fearful look crossed his face, like he felt like he'd just fade away entirely. In response, I stopped that and decided to start growing him in all the places girls grew more than boys. His hips widened and his butt enlarged, and his chest pricked up. His nipples enlarged and grew sensitive and his chest expanded outwards, until he had soft, perky breasts. Now I honed in on what lay between his legs, and before his eyes his penis shrank away. His testicles pulled up inside him and reshaped into ovaries, and his scrotum sank into him until only a flat mound remained, at the centre of which a vagina formed.
Dusty, as I had rechristened her, gasped in shock at her now female body, not even noticing her girlish voice, and rushed to the mirror to look at herself. I could tell how she felt- a deep feeling of loss from not being a boy anymore. And frankly, I thought she deserved it.