While a male is taking a piss, the penis is clamped down upon preventing further discharge resulting in an internal backup of fluids (aka a water hammer) that causes extreme pain.
I was taking a shower with my girlfriend and had to pee, so I pissed on her feet and she turned around and grabbed my junk causing a pee hammer.
by UnCivil Engineer December 19, 2011
when a guy has a bladder problem and pees out of his anus and or rectum
the doctor say he has a pee hammer
by santinochristain May 14, 2011