"We're going to the store," said Jon. After all, maybe he could find his mother and swap back.
"I don't want to go to the store," said Mikey. "It's boring. I meant we should do something fun."
"Well," said Jon, "I wish that you'd come anyway."
Jon had to make another wish to figure out which store his mother went to. Fortunately, it was a department store. He entered with Mikey, holding Mikey's hand, and Mikey snatched his hand away and ran away towards the toy department.
Jon didn't particularly want to lose Mikey in the process of looking for his mother, and went to the toy department to find him. He saw him holding up a plastic gun and going "bang" to a kid.
"Mikey..." said Jon.
"I'm coming," he said. Then Mikey turned to the other kid and said "My Mom's going to get mad if I don't come."
Jon looked around, but didn't see anyone. Neither did Mikey's friend, who said "Your Mom?"
"Yeah, my Mom is called Jon. I know, it's weird, but we're used to it."
Jon had his mother's genitals, and those had given birth to Mikey, and apparently the easiest way for the stone to make the changes not noticed by the people they happened to were to make them not noticed by anyone at all....