"Oh, we were going to get some ice cream, sit down, and figure out just what we can do with the stone."
"Yeah," said Karyn, "but we didn't expect to run into you here. Anyway, you two can talk for a while, I need to use the ladies' room."
Karyn walked off, and Pete joked, "Hey, why don't you just use the stone so she doesn't have to go to the bathroom? With something like that, you could do all sorts of crazy things."
"You know," said Jon, "that's the silliest use for the stone I've heard. You were just telling me a few seconds ago how dangerous it was. You know what's wrong with doing that."
Oops. Pete was thinking about using the stone to get what he wanted too much. And he carelessly made a joke that would be completely out of character for someone who supposedly treats the stone with respect.
"I'm kidding, Jon! I'd never use it for something like that."
Jon seemed a bit puzzled, but shrugged it off. "I know you wouldn't. We have to be really careful. What if I made the bathroom wish and Karyn died? Dead people don't use the bathroom."
"It's not an evil stone, is it? It wouldn't do that."
Unconsciously reaching into his pocket and touching the stone, Jon said "or I might accidentally say something like 'I wish I was your new girlfriend and madly in love with you....'"