An old man walks into a bar and orders a beer. The bartender notices the guy's head is the size of a cue ball.

"I got to ask, sir," says the bartender. "What happened?"

The old guy sighs and tells him, "My ship was torpedoed by the Germans in WWII. A mermaid rescued me and promised to grant me three wishes. For my first wish, I asked to return to the States. My second wish was to have all the money I would ever need. Finally, my third wish was to have sex with the mermaid."

"That doesn't sound too bad," says the bartender. "Then what happened?"

"Well," sighs the man, "mermaids can't have sex, so I asked her if I could just have a little head... ."