the piss used to clear the penal shaft of cum or shit after sex or jerking off. a woman may use the same method after a deposit in her forward hole.
during the afterpiss I hit the toilet tank with a cum/piss mixture due to a semi and the fact it took a moment to figure the combination pressure-to-backsteps ratio needed to ark the fluid into the bowl.
The glorious urination one engages in shortly after an orgasm. It is said to rival that of intoxicated pissing.
The party last night was amazing. I had, like, fifty beers! This chick even blew me! When she was done, I had to pee like a racehorse, so I staggered into the bathroom, had an after piss, and it was THE MOST AMAZING THING EVER.