Originating from the title of a song by Boston
psychopath/frontman GG Allin that was, in fact, actually about being
last in line for a gang bang. The term is somewhat uncommon, but
occasionally used by people in the New England hardcore and punk scenes, where it refers to someone who is late to a trend (or late to drop it), unaware of big news or changes, or generally clueless. It can be used against oneself or a friend in a comically self-depricating fashion, or against someone as an insult.
"What? You guys are gonna meet at O'Malley's in fifteen minutes? Fuck, I had no idea... I'm always last in line
for the gang bang."
"No one told you that the show was cancelled? Shit, dude, you're always last in line
for the gang bang, I swear."
"Of course you're still wearing a Papa Roach shirt. You're always last in line
for the gang bang, you retard."