A small boy is sent to bed by his father. Five minutes later he calls, "Dad!"

"What?"

"I'm thirsty. Can you bring me a drink of water?"

"No. You had your chance. Lights out."

Five minutes later, he calls again, "Dad!"

"WHAT?"

"I'm thirsty. Can I have a drink of water?"

"I told you no! If you ask again I'll have to spank you!"

Five minutes later, "Dad."

"WHAT!"

"When you come in to spank me, can you bring me a drink of water?"