Shum

When a person gets to the max compacity of their shit and sperm to the point it causes pain then releases both the shit and the cum at once to feel the maximum relief known to man. Shum

Or

When you feel pleasure and intoxication at the same time but cannot which is more important so you decide to do it at the same time.

Friend: stfu before I kiss you baby girl
You: be right back I gotta shum real quick