Little Tommy is at the zoo on a school visit and he spots a deer. Being a 
city kid he's never seen one before and so he asks his teacher, "What's 
that, Miss?"
Miss decides to play a word game with him and says, "That's what your 
Daddy calls Mummy, Tommy."
Tommy thinks for a moment and then says, "I'm not stupid Miss, I know that 
ain't a fucking pig!"