When you think you are about to ejaculate, but instead end up pissing all over the place. Most people don't realise that they are pissjaculating until they discover that what they think is semen keeps flowing.
Wow Dom! I didn't realise you were going to pissjaculate everywhere!?
When you jack off so many times in a day that your offsprings get mixed in piss instead of seminal plasma.
Edward: Dude, I just jerked off like 6 times and I pissjaculated on myself and it was white!
Aaron: Why the fuck are you telling me this?