A 7 year old boy has a scary dream and decides to go to the comfort of mom and dad's room.  Nearing the room he hears noises.  Slowly opening the door he sees mom on top of dad riding cowgirl.  Deciding he shouldn't interrupt he returns quietly to his room.  Next morning after dad has gone to work the boy is having breakfast, told his mom what he saw the night before, and asked what she was doing.  Stunned, the mom had to quickly come up with an answer.  She reminded her son of the fact his dad has a bit of a beer gut and that she was merely helping him slim down by jumping on him to get rid of the excess air in his tummy.

The following morning, again at breakfast, the boy said he had been thinking about her answer and that she really shouldn't be going to all that effort.  Why, she asked?  He answered, because even though you try to help dad, every Thursday night when you are at book club that cute young lady from down the block comes over and blows him back up.