Two brothers, Bob and George, both work for a lumberyard.
One day, Bob tells George that he can tell what any piece of wood is just by smelling it.
Unbelieving, George blindfolds Bob and proceeds to test the theory.
The first piece of wood Bob smells, he instantly identifies as maple.
The second piece Bob instantly identifies as walnut.
George cannot believe Bob can really do this, so he takes an old piece of wood and whispers to the secretary to rub the wood between her legs. She happily runs it up in her crotch.
George hands the piece of wood to Bob.
Bob smells it three times.
“I am stumped. But I would have to guess that this wood is either a pussywillow or a shingle from a shithouse. “
This joke is included in the Black Book of Jokes. You can order it from here.