A boy asks his Dad the difference between potential and reality.  His Dad replied, "Go ask your sister if she would sleep with Brad Pitt for a million dollars and then ask your Mom if she would sleep with Hugh Jackman for a million dollars."

So the boys does as his father asks and after getting affirmative answers from both his mother and his sister returns to his father who asks him if he figured it out.

The boy says, "I think so.  Basically we are potentially sitting on $2 million, but in reality we are living with a couple of whores."

Father laughs and says, "lesson learned son, lesson learned."