Is it normal that i'm turned on when my girlfriend pisses in public?

At a camping event, I pissed off in the woods, and to my suprise my gf followed me, watched me, then had me watch her piss. then it escalated from there.

She's pissing in public all over, on streets, alleys, stores of all kinds, even on the ground when we ate outside at a picnic table at a hot dog place. Its never been a sexual thing really, just a risky rush thing.

One weekend, we left our friends apartment back to our car. I forgot to piss before we left, and we had a long drive, so I was contemplating going back, but she pulls me over between a few cars and says do it here. It had just stopped pouring out, and she says no will notice more wetness on their car. I pull my dick out to piss and she says here you need a target, and jams her foot into the side of the car the rubs in a spot, leaving mud on the side of the door. Crazy, but I pissed on the spot to wash the mud away. She then says me too, and she puts her foot up on the fender and pissed on the car too.

My dick was hard by the time I was done watching her. Shes sees it and just looks at me. She finishes pissing, puts her leg down and I grabbed her, pushed her back onto the hood of the sports car behind us and we made out hard. She didn't put her panties back on, and my dick was already out, so I pounded her hard ignoring the wet hood and the new downpour that started. We tried to be carefull on the hood but after a while of pashion we ignored the denting in sounds of the hood. I don't think I came as hard as that since.

I'm not into watersports at all, and never want anyone to piss on me, etc, but watching her was so sexy. Was it the pissing that turned me on? the risky naughtyness of pissing or fucking on someone's car? Combiniation? Anyone else experience such a strange sexual turnon?