The act of pouring molten wax down into the head of the penis, then violently masturbating until ejaculation, so the semen builds up in the shaft and eventually ruptures the penis from the inside.
Doctor: So... how did this happen?
Patient: Uhmm, last night i was jalting before dinner, and i kind of went beast mode, so it kinda... you now.
Doctor: Ha, well that makes two of us.