Mummy takes little Johnny to the zoo. As they pass the elephant cage, the elephant has an erection.

"What's that, Mummy?" asks the child.

"It's Nothing, Johnny, NOTHING." says the embarrassed mother, swiftly leading him on.

A week later Johnny's dad takes him and the same happens.

"What's that, Daddy?"

"That, son, is a 24 inch penis."

"But Mummy said that's Nothing."

"Your mother's spoilt, Son."