Little Johnny walks in on his grandfather smoking a cigar.
“May I smoke a cigar?” asks Johnny.
The grandpa replies, “Well, does your dick touch your asshole?”
Johnny replied, “No,” and left the room.
The next day Johnny sees his grandpa getting into a car.
“Can I drive the car?” asks Johnny.
“Does your dick touch your asshole?”
“No.”
The day after that, Grandpa sees Johnny about to eat a cookie.
“Johnny, may I have some of your cookie?” asked the grandpa.
“Does your dick touch your asshole, grandpa?”
“Yep.”
“Then go fuck yourself, this is my cookie.”