A guy walks into a bar with a pet alligator by his side. He puts the alligator up on the bar and turns to the astonished patrons.
"I'll make you a deal. I'll open this alligator's mouth and place my genitals inside. Then the gator will close his mouth for one minute. He'll then open his mouth, and I'll remove my unit unscathed. In return for witnessing this spectacle, each of you will buy me a drink."
The crowd murmurs their approval. The man stands up on the bar, drops his trousers, and places his privates in the alligator's open mouth. The gator closes his mouth as the crowd gasps. After a minute, the man grabs a beer bottle and raps the alligator hard on the top its head. The gator opens his mouth, and the man removes his genitals, unscathed, as promised. The crowd cheers, and he receives the first of his free drinks.
The man stands up again and makes another offer: "I'll pay anyone $100 who's willing to give it a try."
A hush falls over the crowd. A moment later, a hand goes up in the back of the bar.
"I'll try," says a small woman, "but you have to promise not to hit me on the head with the beer bottle."