Jon agreed with the idea. "I wish that the wish to be whoever I desire means my desire to turn into them, not sexual desire, so that I only change when I want to." Now he wouldn't be stuck as Karyn and could change back to Jon--he'd better use the stone so he could change reality too. "I wish I was Jon again."
A moment later, everything was back to normal, except that his birthday would stay the same as Karyn's, but all things considered, that was pretty minor.
And except, of course, for the wish that Dan and him could have a good time together without losing the stone. But then, that wish had affected Jon's feelings--he didn't want to reverse that wish.
Jon transformed into a girl again, using his own power to be whoever he desires. "How do I look?" s/he asked.
"You look lovely," said Dan.
"I'm glad you think so," said Jon. She hadn't used a body identical to Karyn this time, to avoid confusion. Jon's new female body was more like a female version of her male body, and she was afraid Dan might not like it.
It was a very simple idea. Jon could go back to his own life, and be a guy again. There was only one thing he wanted to be female for--to be Dan's girlfriend. This way he could be himself, except that whenever he went out with Dan or did anything together with Dan, he could change into a girl and be Dan's girlfriend until it was over.
Though Jon did, briefly, wonder what Karyn or his family would say if they found out he was becoming a girl so he could see Dan....