Grandpa and Grandson went for fishing

Grandpa and Grandson go out together for a day’s fishing.
At lunchtime, the man opens a can of cider.
“Can I have some, Grandpa?” asks the boy.
“I tell you what, son,” replies Grandpa. “Can your willy
touch your backside?”
“No, Grandpa.”
“Then you can’t have any cider.”
Later on, Grandpa gets out his cigarettes.
“Can I have one, Grandpa?”
Grandpa replies, “Can your willy touch your backside?”
“No.”
“Then it’s no to a cigarette.”
On the way home, they pass a newsagent’s and each of them
buys a scratch card. Grandpa wins nothing, Grandson wins
£2,000.
“Are you going to share some of your winnings with me,
son?” asks Grandpa.
The boy replies, “I tell you what, can your willy touch your
backside?”
“It sure can,” replies Grandpa confidently.
“Then go fu*k yourself.”