The moment where, when you're taking a shit, a large pocket of gas (referred to as a future-fart) that was resting mid-shit or between two shits escapes as you're passing your lovelog, resulting in a sudden violent fart than not only propels your previously freefalling turd at Mach 2 speeds, but also results in a pleasing shotgun blast of turdlings across the toilet bowl.
A backfire is so named for it's similarity to a car backfiring.
"Man, I was taking a dump and backfired, and now I get 'Nam flashbacks when I visit the shitter."
When you're about to fart, and something extra (and usually liquid) explodes out of the ass.
I was going to light my fart on fire at the party, but a few seconds later everyone got hit by my backfire.
When a guy cums so hard, he ejaculates into his own face.
Dudes, I hella thought she was going to swallow, but she totes made me backfire.
when a guy cums hard enough to blow his load into his own face.
I thought she was going to finish the job, but she pulled off early, and I backfired.
When a guy receives a blowjob and cums so hard it hits him in his face.
Dude, I was getting this wicked BJ and I thought she was going to swallow, but she made me backfire.
To hit back.
When you are clogging the toilet with your massive, brown logs of divine terror, the brown water that splashes up on your butt and balls is known as a "backfire".
Dayum, that shit really backfired.
When a guy cums so hard he ejaculates on his own face.
Dude, I thought she was going to swallow but she totes made me backfire!