A mother tells her little boy, "Johnny, you mustn't eat too many lollies or I'll hide the lolly jar."
Johnny asks, "Why?"
His mother says, "Because something bad will happen! Your tummy will blow up big like a balloon and then pop!"
The next day at church, the boy is sitting next to a pregnant woman.
He points to her belly smiling and says, "I know what you've been doing!"