Priest

Johnny is walking along and a priest is coming the other way. Johnny says, "Hey, mister, why are you wearing your collar backwards? "
The priest says, "Because I'm a father. "
Johnny says, "Yeah? Well, my old man's got three kids and he don't wear his collar backwards. "
The priest says "You don't understand, son. I have thousands of children. "
Johnny says, "You should wear your trousers backwards. "