When a man drinks a lot of water, and urinates into his partner’s tight asshole, as if an air tanker is refueling an airplane. The partner then shits the smelly poop juice out, carrying out the fuel dump.
I was fucking Sarah in the ass, but needed to piss. She told me to piss inside her ass, and she proceeded to do a fuel dump onto my chest.
An excuse for people to do dumbthings. Translates to "you only live once" which is true. However, this is a surefire way to shorten that one life. Don't be stupid.