Magic watch
 

A man walks into a bar next to an extremely hot girl and immediately looks at his watch.
She says, "Is your date late or something"
He says, "No I just got this magic watch".
"What does your watch do that is so amazing?" asked the lady.
"It tells me what is happening."
"What does it say now asked the lady."
"It says you're not wearing panties."
"Well your watch is wrong, I do have panties on."
"Sorry, my watch is one hour fast."