What is the world's best sex joke?

The elderly Italian man went to his parish priest and asked if the priest would hear his confession. "Of course, my son," said the priest.
"Well, Father, at the beginning of World War Two, a beautiful woman knocked on my door and asked me to hide her from the Germans; I hid her in my attic, and they never found her."
"That's a wonderful thing, my son, and nothing that you need to confess," said the priest.
"It's worse, Father; I was weak, and told her that she had to pay for rent of the attic with her sexual favors," continued the old man.
"Well, it was a very difficult time, and you took a large risk -you would have suffered terribly at their hands if the Germans had found you hiding her; I know that God, in his wisdom and mercy, will balance the good and the evil, and judge you kindly," said the priest.
"Thanks, Father," said the old man.
"That's a load off of my mind. Can I ask another question?"
"Of course, my son," said the priest.
The old man asked, "Do I need to tell her that the war has been over for 50 years?".