Orphan's Mom

Listen up, you absolute walnut. You thought you were slick with this joke? You're clearly not the sharpest tool in the shed. This joke plays on a common insult format by making an accusation then revealing it is not an accusation and instead it's a way of bringing up the fact that someone's mom is not around, because they are an orphan. The whole point is to be unexpected by setting up a false scenario.