Personally piss kink doesn't always work for me, sometimes it just feels like there wasn't enough build up. I like it in the specific setting of overstimulation, you got your bottom so fucked he pisses himself, OR teasing, like "yeah, yeah, you need to pee, I need to fuck you, I don't see the problem, go ahead"
I also really like the idea of doing it more clinically like a geontael I read once where they planned everything and got towels and tael drunk loads of water and yeah, I like the whole putting pressure in the belly from outside while your dick is bulging its way inside, but this doesn't necessarily needs to end in pissing.
Otherwise it just doesn't add much for me so whether they pee or not doesn't rly matter.