A man and his grandson are fishing by a peaceful lake beneath some weeping willow trees.  The man takes out a cigarette and lights it.

His grandson says, "Grandpa, Can I try some of your cigarette?"

"Can you touch your asshole with your penis?" he says.

"No," says the little boy.

"Then you're not big enough."

A few more minutes pass, and the man takes a beer our of his cooler and opens it.

The little boy says, "Grandpa, can I have some of your beer?"

"Can you touch your asshole with your penis?", he says.

"No," says the little boy.

"Then you're not old enough."

Time passes and they continue to fish.  The little boy gets hungry and he reaches into his lunch box, takes out a bag of cookies and eats one.

The grandfather looks at him and says, "Hey they look good. Can I have one of your cookies?"

"Can you touch your asshole with your penis?" says the little boy.

"I most certainly can!" says the grandfather.

"Then go fuck yourself," says the boy, "These are my cookies!"