A mother and father took their 6 year old son to a nude beach.  As
the boy walked along the beach, he noticed that some of the ladies had
boobs bigger than his mother's and asked her why. She told her
son,  "The bigger they are, the dumber the person is." The boy, pleased
with the answer, goes to play in the ocean but returns to tell his
mother that many of the men have larger members than his dad. His mother
replied,  "The bigger they are the dumber the person is."  Again satisfied
with his answer, the boy returns to the ocean to play. Shortly after, the
boy returned again.  He promptly told his mother, "Daddy is talking to
the dumbest girl on the beach and the longer he talks, the dumber he
gets.