Necklace of Truth: Which Girl Did Karyn Have Sex With?

"Karyn. If I were a girl, would you have sex with me?" Jon asked. "Yes. Definitely." She felt a bit embarrassed saying that, but it was the truth. In fact, ever since she found out about the existence of the wishing stone, she had been thinking of ways to talk Jon into making himself a girl, just for that reason. "The girl that you had sex with. Do I know her?" Jon asked, getting back to her secret past. Karyn asked him to stop prying, but he just needed to know. "Yes," she answered. "Who is she?" he asked. "She's ..." Karyn began, being forced to tell the truth.