About a year after graduating high school, a couple friends and I decided to go camping for one night as a mini-high school reunion. Since we were all poor college kids, we camped at this free campsite that basically was just a field with a couple porta potties about a 1/4 mile away. After an evening of drinking, I woke up about 2am in the tent I was sharing with my friends and really had to pee. Like REALLY had to pee.
Since I am a girl and I didn't want to risk peeing all over myself squatting against a tree, I decided to make my way to the porta potties. Unfortunately, my cell phone (which I was using as a flash light) died about half way there. Although I was kind of freaked out, I thought, "Well I already made it this far," and kept going.
I got to the bathroom, couldn't see a thing but did my thing, walked back to the tent and laid down. I noticed that I smelled something that smelled like shit, but I thought that someone must have farted in the tent or maybe I had stepped on poop in the porta potty or something and my shoes that I had left outside the tent smelled. But, I figured I would clean my shoes in the morning, and went to sleep.
In the morning, I woke up still smelled a shit-like smell. I got kind of worried that I had shit on my hand or something so I walked to the porta potties. One of them (the one I had used during the previous day during fun drinking time) was in good condition. Then I looked at the one that I had used in the middle of the night. I basically threw up in my mouth when I saw it. There was shit everywhere. Wiped all over the toilet seat, all over the walls, all over the door. The realization that I had sat on a toilet seat covered in someone else's nasty shit the night before and then slept with that on my butt all night made me want to throw up.
Needless to say, I told my friends I had to find a shower ASAP and we were able to find another friend who lived locally to let me use his shower. I still cringe when I think about that night. But I learned a good lesson. Never sit on a toilet seat without checking it out first.
TL;DR: Sat on a toilet seat that was covered in shit and didn't realize I had shit on my butt until about 6 hours later.