Realistically

The father thought for a moment, then answered, "Go ask your mother if she would sleep with Robert Redford for a million dollars. Then ask your sister if she would sleep with Brad Pitt for a million dollars. Come back and tell me what you learn from that."

So the boy went to his mother and asked, "Would you sleep with Robert Redford for a million dollars?"
The mother replied, "Of course I would! I wouldn't pass up an opportunity like that."

The boy then went to his sister and asked, "Would you sleep with Brad Pitt for a million dollars?"
The girl replied, "Oh my God! I would just love to do that! I would be nuts to pass up that opportunity!"

The boy pondered the answers for a few days, then went back to his dad. His father asked him, "Did you find out the difference between potential and realistic?"

The boy replied, "Yes, sir. Potentially, we're sitting on two million dollars, but realistically, we're just living with two sluts."