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
Person #1: "I'm going to kill myself."
Person #2: "Go for it!"
Person #1: "What would you do if I actually did it?"
Person #2: "I won't attend your funeral, but I'll send my letter of approval."
Random Eavesdropping Bystander: "BANG BANG"
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
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.