A college professor always started off his lectures by telling an obscene and drity joke to the students.
Finally, two girls got fed up with this and decided to walk out of the classroom the next time he did this. But the proffessor found out about this and the next day he came into his class and began, “Did any of you hear about the whore shortage in Indiana?”
Just then the two girls stomped out of the room.
The proffessor called to them, “Wait girls, the train doesn’t leave until tomorrow!”