One night a father sent his son

One night a father sent his son upstairs to bed. Six
minutes later the boy screamed, ''Dad! Can you get me a
glass of water!?!''

''No. You had your chance. Be quiet and go to sleep.''

A minute later the boy screamed, ''Dad!! Can you PLEASE get
me a glass of water?''

''No. You had your chance. Next time you ask I'll come up
there and spank you.''

A minute later the boy yelled, ''Dad, when you come up to
spank me can you bring me a glass of water?''