I wank to lots of different porn, but one of the main sources of stimulation is voyeur videos of women pissing. Either from below or behind the bowl, or when they are out in the woods or a car park.
When I see the incredible closeups you sometimes get on the pro videos when the camera is somehow mounted inside the bowl and the ladies squat/sit right on top and their cunt lips open and muscles surge and the flow comes, I always have a chuckle when their lips are so stuck together (I love big thick labia) that it comes out sideways and is all over the buttocks and thighs. There are drips everywhere. In so many instances the ladies don't wipe, maybe sometimes a cursory flick through with their hands even, and up go the panties/jeans and they act as a drying agent for all that stray piss.
Then you go into a men's urinal. Now - we are supposed to have this aim mechanism/tool, but when you see the mess on the floor in just about every toilet, you have to wonder who is the worst offender.