This little boy is visiting the zoo with his father. They stop to have a look at an elephant and the kid just stares at it in fascination. Eventually he asks his father, "Dad, what's that thing hanging down?"

"That's the elephant's trunk," replies his father.

"No, I mean at the other end."

"Oh, that's the elephant's penis."

"That's funny," mused the little boy, "Last time we were here, Mum told me it was nothing."

"Well," said the smiling father, "You have to remember that your mother is a very spoilt woman."