Thanks, says the guy, "It's the cutting edge of technology. I can telepathically ask this watch anything I want to know, and it'll answer me, telepathically."
"Rubbish," says the girl.
"No, it's true," says that guy. "Look, tell you what, I'll prove it. I'll ask it if you've got any panties on."
The guy scrunches up his eyes for a moment, as if concentrating hard to talk to his watch, then opens them and says, "Nope, it says you haven't got any panties on."
"Well, it's wrong," says the girl, "I do have panties on."
"Damn," says the guy, slapping his watch, "it's an hour fast!"