The small yet numerous particles of urine that are reflected back at you when you pee into a urinal/toilet bowl. This phenomena usually happens when too much force is exerted when trying to force the urine out, causing the pee to have such a high velocity that when it strikes the surface (either water or porcelian) it instantly atomizes and reflects back toward the direction where it originated from.
To slap a stream of urine back and forth with one's flat-palmed hand. Can be a solo or group activity performed by either gender. Generally practised at urinals and public toilets.
"My game was on point that night, I pisswhacked at a rate of 329wpm (whacks per minute)"
"I pisswhacked the shit outta this guy's stream at the urinal last night, his expression was one of liberation"
"Some guy started pisswhacking me at the urinal, the experience has brought me closer to Jesus"
The need to urinate occurring during masturbation. Continuing to ejaculation often results in a less pleasurable orgasm. This often happens upon waking up with morning wood.
John woke up with a hard-on but he also needed a piss. He struggled on and after his ejaculationwondered why he had bothered with his pisswank after all.