A guy goes to the supermarket and notices a gorgeous 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"
Stunned, his mind travels back to the only time he has ever been unfaithful to his wife and he says "My God are you the stripper from my stag party that I banged over the pool table with all my mates watching, while your partner whipped my ass with wet celery ????"
She looks into his eyes and calmly says, " Nooo, I'm your son's maths teacher"