A guy goes to the supermarket and notices a beautiful blond woman wave
at him and say 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."

Now his mind travels back to the only time he has ever been unfaithful
to his wife and says, "My God, are you the stripper from my bachelor
party that I made love to on the pool table with all my buddies
watching, while your partner whipped my butt with wet celery???"

She looks into his eyes and calmly says, "No, I'm your son's math
teacher.