Scummy Cummy

When one ejaculates, but immediately prior to doing so, pulls their underwear and undergarments over their genital area, resulting in the cumshot being contained, but having a huge, obvious cumshot staining the crotch of the person.

Person A: "You see Person C lately? I can't believe it, they had a Scummy Cummy dead and centre."
Person B: "Holy shit, how big was it?"
Person A: "Looked like they pissed themselves, they must've done it in a hurry."