"Bring me a glass of water" joke

A small boy is sent to bed by his father. Five minutes later:

"Da-ad..."

"What?"

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

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

Five minutes later: "Da-aaaad..."

"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... "Daaaa-aaaad..."

"WHAT??!!"

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