LMAO@ this thread.
Priceless
Just tell her you'll clean and wipe after you pee, really that is just common courtesy to others using the bathroom. The problem isn't that you pee standing, the problem is that the bathroom is unclean. So solve the real problem. Also, I don't think there's a problem in actually sitting, but that someone is telling you what position to take when doing a private thing behind closed doors.