I've never peed in a pool that I could remember. I'd never do it in a public pool though. Maybe on my own?
I remember coming really close once by accident. O_O I was just in a pool and I nearly peed myself laughing (it wasn't even a really big laugh, I was just chuckling and then I felt it nearly come out, it was actually recent, like last summer or 2 summers ago. Weird....I've never even reached that close any other time in my life.