Very few piss. Female ejaculation (just not to the level you see in porn films) is much more common than most think. Most guys just never get their girl to cum.
First time the chick in my ava come on my face while I was eating her out, I thought she pissed. I was like "holy shit, what the fuck"
Took a bit to figure out what's what, happens with a lot of the chicks I'm with now.