Father, mother and son decide to go to the zoo one day. So
they set off and are seeing lots of animals. Eventually they
end up opposite the elephant house. The boy looks at the
elephant, sees its willy, points to it and says, "Mummy, what
is that long thing?" 
His mother replies, "That, son, is the elephant's trunk." 
"No, at the other end."
"That, son is the tail." 
"No, mummy, the thing under the elephant." 
A short embarrassed silence after which she replies,
"That's nothing." 
The mother goes to buy some ice-cream and the boy, not being
satisfied with her answer, asks his father the same question.
"Daddy, what is that long thing?" 
"That's the trunk, son," replies the father.
"No at the other end." 
"Oh, that is the tail." 
"No, no daddy, the thing below," asks the son in desperation. 
"That is the elephants penis. Why do you ask son?" 
"Well mummy said it was nothing," says the boy. 
Replies the father: "I tell you, I spoil that woman ..."