Boj/ BOJ

Giving a blowjob and taking a shit simultaneously.

This is the reverse of a blumpkin.

Etymology
Boj is a portmanteu of the word bog and the slang BJ.
Bog; to take a shit (Australian English)
BJ; abbrev. Blowjob (English)

Bog + BJ = Boj

Hey mate, I'm just gonna go have a quick Boj/ BOJ I will be out in a minute.