A little boy walks into his parents' bedroom to find his mother on top of his father, humping up and down. The mother spots her son and dismounts as the boy leaves the room. Worried about what her son has seen, the mom quickly dresses and goes to find him in his bedroom.
The son asks, "What were you doing to Daddy, Mom?"
The Mom replies, "Well, you know how Dad has a big tummy?"
The boy answers, "Yes he sure does." "Well,I have to get on it sometimes to help flatten it," explained Mom. The boy says, "You're just wasting your time, that will never work."
The Mom is confused, "Why not, son?"
"Because whenever you go shopping, the lady across the street comes over, gets down on her knees in the bedroom, and blows his tummy back up!"