LSFI: Let Shit Fuck Itself. Let things take care of themselves, especially if they are crappy things that one is not too interested in taking care of anyway. Alternatively, could also mean let those things go to hell, i.e. NOT take care of themselves, 'just don't bother me about them because I couldn't care less about them'.

Variants include LTSFI, which can stand for Let This Shit Fuck Itself, OR Let That Shit Fuck Itself. A more aggressive variant is LTSFM - Let That Shit Fuck Me. This slightly changes the connotation from things just going to hell, to things becoming an active problem in one's own life, screwing with one.
Dude: "Man, did you hear Britney bitching out Taylor in front of Vanessa?! I mean, Vanessa is Taylor's bff! shit's going to hit the fan when this gets back to Taylor! What are we gonna do if Britney throws a hissy fit and bombs our gig??"
OtherDude: "Man, relax, it's not our problem. LSFI."

Guy1: "Dude, your bank account if overdrawn, your credit card is near its limit, and you have barely 10 dollars in your wallet... hadn't you better get your shit together??"
Guy2: "Meh, forget it man. LTSFM."
by Ashish Dha October 12, 2013
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