Two parents take their son on a vacation to a nude beach. The father goes for a walk on the beach, and the son goes and plays in the water.

The son comes running up to his mom and says, "Mommy, I saw ladies with breasts a lot bigger than yours!"

The mom says, "The bigger they are, the dumber they are."

So he goes back to play.

Minutes later, he runs back and says, "Mommy, I saw men with penises a lot bigger than Daddy's!"

The mom says, "The bigger they are, the dumber they are."

So he goes back to play.

Several minutes later, he comes running back and says, "Mommy, I just saw Daddy talking to the dumbest lady I ever saw, and the more they talked, the dumber he got!"