Prostitute joke

After supper, the little boy and girl are sitting on their Daddy's knee by the fireplace while he enjoys his evening pipe and a glass of port.

"Daddy, daddy?" asks the little boy "How did you and Mummy choose our names?"

"Yes," chirps the little girl, "tell us, how did you decide on our names?"

"Well, Carmen, you were both named after your mother," says Daddy to the little girl, between puffs of smoke.

"But Daddy - Mummy is called Julia! That's what you and the other grown-ups call her!" giggled the little Carmen.

"I know - but when I first visited your mother, she was working as a prostitute in town, and she used to pretend to be called 'Carmen' to make it more exciting for her customers. Then we fell in love, got married and we had you two wonderful children," beamed Daddy, sipping a little more port.

"You said we we both named after her - so how did you choose my name?" asked the little boy.

"Well," began Daddy, patting the little boy on the head thoughtfully, "Perhaps I should explain what a prostitute actually does, Nicholas..."