A guy goes to the supermarket and notices an attractive woman waving at him.
She says "Hello!!!".
He's rather taken aback because he can't place where he knows her from.
So he says... "do you know me???"... to which she replies..."
I think you're the father of one of my kids"....
Completely shocked...the guy's mind travels back to the only time when he was unfaithful to his wife and says..." My God!... are you the stri**er from my bachelor party that i made love to on the pool table???!!"
Confused... she looks into his eyes and says calmly..." No... I am your son's teacher"