Something like this happened to my wife. We were in a tent and the zipper was stuck closed late at night. She was beyond desperate and give in to peeing in an empty water bottle. 

I think my biggest fantasy is peeing while someone watches. Or having someone walk in on me in a public restroom. Like maybe I forget to lock the bathroom door or something and some stranger walks in on me. I'd have my legs spread apart while I'm on the toilet and they'd be able to see my pussy while I'm peeing.

I wish there was some accepted norm and that as a kid someone would have told me what that was openly, like a coach, parent or someone of authority. It's weird to me that people tell me all the time that years ago guys weren't at all concerned about nudity or where they pissed, I wonder what changed to make guys so much more timid these days. I also don't quite get why it's seemingly alright to pee openly in the locker rooms while changing, but on the pool deck, even when it's only guys at practice, those of us who have always pee through our speedo suits. It disguises the fact we're peeing a bit, but what's the difference if we don't feel the need to disguise it in the locker room, it's the same group of guys peeing on the same type of floor, but yet the habits are completely different.

Dad was working on fixing our toilet, but unfortunately it took a few days to complete. In those few days, we tried to use the toilet as little as possible, either peeing while we were out of the house or running up to a gas station to use the bathroom. One of those nights, it was like 3 in the morning and I had to use the bathroom very badly. I didn't have my license at the time, so I couldn't just run to a 24 hour station and pee. I very nearly considered putting on a skirt and going out in the front yard to kneel down and pee, but I was terrified that someone would see me, even though the chance of that happening was very unlikely. What I finally ended up doing was grabbing a huge glass mug, like basically a tall beer stein, and peeing into it. I honestly cannot believe how full that glass got, I'd been holding it for hours. It felt incredible.