Eh, I think cleaning my bong makes the sink much dirtier. Which is also why I clean it pretty often. And rarely piss in the sink.

But sometimes.

And to be honest I wouldn't mind a girl pissing there either, just don't see why anyone would bother. I also don't mind pissing in the shower, again, given that you actually don't piss all over the walls and also clean your shower.

But like a bit of well hydrated watery pee is nothing. A foul dark dehydrated after exercise piss is different, that's not as much for the shower or sink. That's for the loo.