For me, one of the main reasons I pee in the shower is for the sake of cleanliness. If you feel the need to pee midshower and you step out of the shower, walk to the toilet, pee, then walk back into the shower that leaves a lot of water on the floor. It's even worse if you are female. We have to sit down. This scenario brings up the totally valid point of waiting until you're finished with the shower to dry off and pee. A normaladult with a well functioning bladder would have no problem with that. However I personally really value that feeling of cleanliness you get after a shower. To me, it seems counterproductive to sit on the toilet and then flush and possibly be exposed to the spray from the toilet. Which really rustles my jimmies. It is like peeing in a pool to avoid getting up and using the restrooms. Except there's no one else in the pool and there's a constant flow of water washing everything away. If there happens to be someone else with you in the shower, I do not recommend peeing on them. Unless of course they're into that.