Jon picked up the stone and said "I wish that Karyn's male genitals were back on my body, and that my female genitals were back on her body."
A familiar sensation swept through Jon and Karyn. Karyn looked down her pants and was relieved to see that the bulge had vanished from her panties. Jon reached down and patted his penis to reassure himself that it was there.
Strangely, while Jon could feel his penis back where it belonged, something didn't feel right. He patted it again. He started to panic - he didn't seem to have any sensation in his penis! Jon reached down his pants, ignoring Karyn, and grabbed his penis as hard as he could, trying to get some sensation from it.
"Ow!" shouted Karyn, as an uncomfortable and unfamiliar pain shot up from her groin. Jon ignored her, terrified that he had lost all feeling in his genitals.
Karyn grabbed Jon and pushed him down, saying "Jon, (ow!) stop it (ow!)." When she finally got Jon's attention, she explained.
"Jon, you wished for my genitals to be on your body, and for your genitals to be on my body. I think that the stone made it so that they're still our OWN genitals! That's why I can feel what you're doing, and you can't!"
Jon looked at Karyn, confused. Karyn said, "Watch this."
Karyn reached down the front of her panties and gently stroked her clitoris. Jon jumped up as he felt an erotic tingle from his groin.
"Oh my God!" he said, "how do we fix this?"