Cheap flight years ago. Back aisle seat, right next to the toilet.
Full disclosure: I don't even piss on planes. I don't understand how people can't hold it.
This giant motherfucker sets up shop in the toilet, and I can hear him over the sound of the engines. Eventually, he's been in there so long that I can smell him. It was beyond rancid. There's an Arby's joke above, but this dude smelled like he was eating Arby's that other people had already eaten and shat out. Everybody in the back was half-gagging.
There was only one toilet, and this woman comes up with a bit of urgency, walks through the stench and actually knocks on the door. No response, she runs back to her seat.
She comes back a few minutes later and is beating on the door where Captain Sulfur is still going at it. I'm slunk down in my seat with my shirt over my nose, so I'm claustrophobically eye-level with a desperate woman's crotch when she pissed her pants Michael Bay style.. maybe a foot away from my head.
She ran crying and dripping back to her seat, and when we landed everyone had to walk around it.