9-year-old lad won't go to sleep one night. Every 10 minutes, he's at the top of the stairs shouting "Dad - I'm hungry" or "Dad - I'm thirsty" or "Dad - I'm too cold" and so on. Neither parent can get him to settle down and, to make matters worse, the door-bell rings at 9.30.
"Dad - who's that"
"It's your Uncle George"
So Uncle George detects an 'atmosphere' in the house and asks if he can help to get the lad to settle down for the night.
"Try if you want, but we've had no success" says the father.
So Uncle George goes upstairs and reappears ten minutes later. Young lad is quiet - very quiet.
Close to midnight, Uncle George is just leaving when the father asks "By the way - how did you get the little git to be so quiet, so quickly?"
"Oh - it was easy; taught him how to wank"