One day a little boy comes home from school and finds his parents having sex. "Hey Daddy," yells the boy, "horsey back ride, horsey back ride." The dad thinks about it for a second and figures it would be harmless. "What the heck," he says. "Get on." So the boy gets on his dads back, and after a few minutes the mother really starts getting into it. "Hang on, Daddy," the boy yells. "This is where me and the pool guy usually get bucked off."