A little boy sees his grandpa smoking a cigar on the porch and asks for a puff. Grandpa says, "Son, can you touch your bad person with your pecker?" and the little boy says "no". Grandpa replies, "Well, then you're not old enough to puff a cigar".
A couple days later the little boy sees his grandpa drinking a beer on the porch and asks for a sip. Grandpa says, "Son, can you touch your bad person with your pecker?" and the little boy says "no". Grandpa replies, "Well, then you're not old enough to drink beer".
The next day, the little boy is sitting on the porch with a plateful of freshly baked chocolate chip cookies that grandma made when grandpa sits down and asks for a cookie. The little boy says, "Grandpa, can you touch your bad person with your pecker?" and grandpa says proudly, "As a matter of fact, I can!"
The little boy says, "In that case, you can go eff yourself. Grandma made these cookies for me!"