There was an old professor who started every class with a vulgar joke. After one particularly nasty joke, Two of the female students in the class decided to walk out on next the next joke.

The professor got wind of this plot, so the next morning he walked in and said, Good morning, class. Did you hear the one about the shortage of hookers in Los Vegas?

With that, the two female students stood up and headed for the door. Wait, ladies, cried the professor. The bus doesnt leave until tomorrow!