A guy is in line at the local Wal-Mart when he notices that a rather
hot blond behind him has just smiled "Hello" to him.
  
He is rather taken aback that such a looker would be waving to him...
and although familiar he can't place where he might know her from...
so he says ..."Sorry....do you know me?"

She replies... "I may be mistaken... but I thought you might be the
father... of one of my children."

His mind shoots back to the one and only time he has been unfaithful.
"Holy crap".... he says, "are you that stripper from my bachelor party
that I screwed on the pool table in front of all my friends.... while
your girlfriend whipped me with some wet celery and stuck a cucumber up
my behind?"

"No".... she replies..... "I'm your son's teacher."