Firefly Could you shine your light
Now I know your ways
'cause they're just like mine
Now I'm justified As I fall in line And it's hard to try
When you're open wide
The act of taking a lit cigarette bud and throwing it at a nearby pedestrian/friend. More often than not, if the victim is not a friend, they will get pissed.
Person 1: Hey, dude?? -Takes a hit from his cigarette-
a firefly is when a man sets his pubes on fire, proceeds to have sex with a woman (lighting her pubes on fire as well) and finishing off by pulling out and using your jizz to extinguish the flames.