"I want you to help me stop my son gambling," an anxious father said to his boy’s principal. "I don’t know where he gets it from but it’s bet, bet, bet."
"Leave it to me," said the principal. A week later he phoned the boy’s father. "I think I’ve cured him," he said.
"How?"
"Well, I saw him looking at my beard and he said, ‘I bet that’s a false beard.’
‘How much?’ I said, and he said "$5 "
"What happened?" asked the father.
"Well, he tugged my beard, which is quite natural, and I made him give me $5. I’m sure that’ll teach him a lesson."
"No, it won’t," said the father. "He bet me $10 this morning that he’d pull your beard with your permission by the end of the week!"