It can be the other buttock.

I went back and I transformed my entire company into a one buttock company.

And I was working with this young pianist and I said, The trouble with you is you're a two buttock player.

The old woman reciprocates by revealing her own tragic life, which included having a buttock cut off in order to feed some starving men.

Jack was a tattoo artist, and gave her the first of a series of tattoos, one of which would become her trademark tattoo, two hearts on her right buttock.