you know what, that reminds me of a funny story(well, funny to me at least), i used to live in a co-op house and in my third year in that house i got one of the nice rooms with a bathroom that was shared with only one other person. that year it was a girl and she was initially not comfortable with sharing a bathroom with a guy. i didn't understand why, it's not like we'd be using it at the same time or anything (it was tiny). so i asked her.
she said "well, guys pee in the shower, and i don't want to shower where you pee."
i was surprised, shocked even, it had never occurred to me to pee in the shower. i assured her that i had never done it and never would.
but the seed was planted. peeing in the shower? what a revolutionary concept! and when we had a falling out later in the year i tired it out. and guess what, i liked it!
Spitting in the shower is actually worse in terms of germs and waste than peeing is.
I take pride in the fact that I can take out one form of responsibility every morning by wizzing in the shower. The last thing I want to do when I wake up is concentrate enough to aim into the pot. I would much rather just let the hot water wake me up as I release nature's fury with no worries.
i've heard the "peeing in the shower is gross" argument and I don't buy it. Once a week I scrub that tub with Ajax, Javex, and any other disinfectant with an X in the name, so I think its pretty clean. And, its not like we pee all over the curtain. How about all the dirt you scrub off yourself? While its not as gross as pee, it is still dirty.