This is similar to the glorious art of a blumpkin, but in this particular case the girl is the one who is on the toilet, either pooping or urinating, preferably urinating since girls don't poop, and the man is standing up in front of her while she is sucking his cock. You may also refer to this thrilling maneuver as an "oppo-blump" since it's pretty much the opposite of a blumkin.

A casual invitation / threat used by an individual that is not afraid of fucking someone up.