Heiny

But look an American dead in the eye and call him a dirty no-good, red-faced Commie? Well, you just took a dump and wiped your heiny with Old Glory. Son – you crossed the line.

Source: wiktionary

Limited space in your shower can cause bottle avalanches, water leaks, and accidental butt brushing. "No more curtain sticking to your heiny!" says one reviewer about the Moen curved shower rod.

Source: wiktionary

While you're tightening your grasp around the mic 'cause you done / shitted on it so much, you're always reminded of your past / 'Cause your heiny's sore, that's / 'Cause you still haven't finished fuckin' wiping your ass

Source: wiktionary