Figure that one out. The memory was fresh in my mind as I watched the kid with cocaine-induced priapism point out that he didn't masturbate because he was Christian.
Priapism is the technical term for a painful, persistent erection.
In detumescence, the valves reverse their positions, and the blood escapes. Low-flow priapism involves the venous return valves being stuck shut, so the blood stays in the penis and can't drain. As you might have guessed, this is the point where the men in the audience are bent over their keyboards and moaning in vicarious pain. Masturbation doesn't seem to help. This is harder than it seems.