A very oldie, but......
A little boy was at the zoo with his parents, at the elephant enclosure. He walked up to his mother and asked, "What's that thing hanging underneath the elephant, mum?"
She looked at the elephant and replied, "That's it's long nose, or trunk, son."
"No, not it's trunk, I know what that is. At the other end.....?" the little boy said.
"Oh! I see what you mean, That's its tail."
The little boy was getting a bit frustrated at this point, and said "No, no. Not it's trunk or its tail. That thing, in front of it's tail."
The mother now saw what he was asking and was somewhat embarassed, so said " Oh, that's nothing. Now stop asking these questions."
The boy was not to be denied this bit of an educational experience so went over to his father.
"What's that thing hanging underneath the elephant, dad?"
He looked at the elephant and replied, "That's it's long nose, or trunk, son."
"No, not it's trunk, I know what that is. At the other end.....?"
"Oh! I see what you mean, That's its tail."
"No, no. Not it's trunk or its tail. That thing, in front of it's tail."
Finally the father clued in to what his son was being inquisitive about. "Oh, now I understand, son. Well, like you and me, that is a boy elephant and that is its penis."
"But dad, why did mum say it was nothing?"
Without missing a beat the boys father answered.......
"Well, she's been spoilt...."