The phrase "bang bang" is a colloquialism used after one has been insulted or humiliated (burned, wrecked, destroyed, told, dissed, etc. work also). This phrase was developed to mimic the sound of dual pistols firing one after another at a target, an analogy to the person who has just been burned being shot down. There is a popular following to the idea that "bang bang" should only be used after one other than the would-be speaker has said "shots fired."

An optional motion one can do while shouting the phrase is pantomine pistol shots firing from your hands as you should each word, using finger guns

the sound you here when a trigger is pulled

sex, screwing, fornication

some saying for lame scene kids.
bang bang usually includes andy warhol guns on their myspace backrounds with hearts and guns and bangy type shit

that is the school shooter coming to kill you well it is school so i would assume he is just doing you a favor you should probably go out and thank him

The process of playing shoot em' up videos games with friends

A phrase that idiotic scene and emo kids put in all their stupid profiles. Usually placed along with a poorly cropped, sparkling 9mm pistol, possibly with some sort of annoyingly colored, bright liquid coming out of the barrel.