Flying has been a hot topic of late. Ever since a door flew off an Alaskan Airlines Boeing 737 Max 9 in early January, Boeing and the airline industry have been under heavy scrutiny as new incidents are piling up faster than your father-in-law can stand up when the plane lands. 

But in all of this aviation turmoil, we've forgotten what the actual worst part of flying always has been: the other people. The People of Walmart are well known as some of the grossest around, but at least you don't have to sit directly next to them for five hours, with no hope of a release unless you're in the emergency exit row and a door is missing a few bolts. Whether passengers are stinky, rowdy, noisy, inappropriate, or some combination of the above, it only takes one rotten apple to ruin the flying experience for everyone, and that's with a smooth ride. 

This gallery features a man who decided to relieve himself on the seat in front of him, and although the seat belt sign is a frequent urinator's worst nightmare, any adult person should be able to contain themselves to a tiny bit of leakage at the most. Here are 21 people of Spirit: the worst airplane passengers.