A man goes into a supermarket and notices a beautiful brunette who waves at him as says “hello”. He’s rather surprised, because he can’t place where he met her.
So, he says “Do you know me?”
To which she replies, “I think you’re the father of one of my children.”
He thinks back to the only time he had ever been unfaithful and says, “My God, are you the stripper from my bachelor party that I had wild sex with on the pool table, with all of my buddies watching, while your partner whipped my butt with wet celery?”
The woman looks him in the eye and calmly replies, “No, I’m your son’s math teacher.”
