The act of trying to fart while a penis is going into your butthole, and when put in with enough velocity the gas bubble makes its way up and you end up burping.
Greg: Man I shoved it in so quick last night right before he farted that it went up and she had the old San Franciscobackfire.
A bulgarian backfire is a Halo 2 term. It is when a player tried to stick another player with a plasma grenade from point blank range, and the plasma bounces off the player and sticks to the person who threw the grenade.
"D00d! Sum n00b stuk m3 wi7h a BulgarianBackfirelast night on Xb0x Live!!!!11!!!11 I wuz s00 pissx0r3d!!!111!!1!1
The guilt you feel after ejaculation if you let your hormones take over your rationalization skills and you become really dirty-minded towards someone else in which there's something to regret afterwards.
Jamal: Dude I sent nudes to Jessica and I felt scared later
Mike: Sounds to me like hormonalbackfire
Refers to da often-moderately-painful experience dat follows an especially "heavy-duty" cough, burp, sneeze, etc. --- a small amount of stomach-acid will travel upwards into the throat and create an acrid burning sensation.
Shortly after consuming a large meal is one of the most notorious times for a bronchial backfire to occur; it's wise to have a large glass of water or milk handy to hastily swig from in case of mishaps like this.