Squirting is a release of urine caused by relaxation of the smooth muscle that regulates the bladder. "Squirting" or urinating can happen voluntarily or not. A full bladder helps. One girlfriend I was fucking hard and long one afternoon suddenly announced, "I have to pee", jumped out of bed and standing over a small throw rug next to the bed with her legs spread, proceeded to piss all over that little rug, while exclaiming, "I just can't help it" and "Oh God, I'm coming". Even though she was coming and pissing at the same time she managed to aim the stream on that small throw rug so as not to mess up the floor, long legs shaking, having a difficult time maintaining her balance. What a trooper! Another time with the same girl, again a hard and long afternoon fuck that got pretty sloppy because I precum alot and she did too, I was giving her a good pounding with her legs pinned back when one stroke must have been a tad too long since the head of my dick slipped down a notch and on the next stroke I found myself buried to the hilt in her virgin asshole. I remained completely buried as she cried out, "I'm coming" (she liked to announce this in a loud voice) while her asshole clamped and unclamped on my fat dick and she let loose a strong stream of piss all over us. All this with her hips bucking, eyes rolled back in her head, completely out of control grunting and groaning her way through a huge orgasm. So this is my experience with squirting: One girl, twice, completely spontaneous.