As Jon got a little frightened, Karyn waited to find out just what Jon had wanted to do to her.
"David?" asked Jon. Jon seemed to be struggling to not say things, but he did finally give in. It was a wish, after all.
"Yes?" replied the half-transformed teenager.
"I want to watch you kiss Sarah, so go kiss Sarah." Which meant that he had wanted to watch Karyn to kiss Sarah. But because of Karyn's wish, Jon had to watch David do it instead. But without any wishes.
Puzzled for only a brief instant, David then said "Sure I will, she's hot!" and began to make out with Sarah. David was only transformed from the waist down, so the top of it looked like a guy and a girl together normally.
"That's enough," said Jon. "Now dry-hump me while taking your clothes off." Jon wanted to rub up against Karyn's body and wished for that, so now he'd tell David to do that instead.
"I'm glad you're letting me do this," said David. "You never did before."
"I don't have any choice!" replied Jon, as David began snuggling up to him and rubbing his transformed hips against Jon's. Then David pulled down his thong, revealing the woman's sex that neither Jon nor Karyn realized was new. He rubbed against Jon, grinning, then when Jon said "that's enough," put the thong back on and backed off.
"See?" said Jon. "That's all I had wanted to do with you, Karyn."
But Karyn wasn't sure. First, she wasn't sure that Jon was finished. For instance, he could have wanted to do something with Karyn later, so he might not be forced to do it with David until later. Second, she wasn't sure if that was all she wanted to wish for...