In a playful, yet scholarly romp through "low" and "high" culture, Jonathan Allan asks why—since we all have one and use it every day—do we squirm at the mere mention of the anus? How is it that Kim Kardashian's derriere can break the internet, Pippa Middleton's behind can create a "butt lift" craze, and yet we cannot handle a discussion of anality? And why, given that we all have one, has the anus been caught up in the very "ground zero of gayness"?