A guy walks into the bathroom and sees a very small man taking a leak. The little man looks at him and says "Hi! I'm a leprechaun! And because I like you, I'm going to grant you three wishes."

The man thinks for a moment and then says "I'd like a beautiful house."

"Granted. When you return home, you will have a gorgeous mansion."

"Great! Now I'd like a beautiful woman."

"Granted. When you return home, you will find a woman so amazing you will never look at another woman again."

"And I would love to have a huge penis."

"For that, you'll have to let me screw you in the ass."

The man hesitates, but since he wants a huge penis, he consents. As they're going at it, the man says "I can't believe I'm letting a leprechaun screw me in the ass!"

The little man says "I can't believe you thought I was a leprechaun."