Brandon Davis -- 'Firecrotch' Originator Burned by Massive Casino Debt

Lindsay Lohan's nemesis Brandon Davis blew through $300k in one amazingly awful Vegas night -- but he was gambling with casino money, and hasn't paid the debt ... so now they want payback.

Brandon -- an heir to the Davis oil fortune -- was sued by the Wynn Las Vegas and the Bellagio for unpaid markers which he got on Nov. 7, 2014. In docs, the casinos say Davis has been ducking them ever since his epic bad luck streak.

So, the Bad Check Diversion Unit of the Clark County D.A.'s Office is stepping in -- ordering Davis to pay at least $9,257/month until he's paid his tab ... which has now ballooned to $323,962.

Pretty funny -- the guy who infamously blasted Lindsay for being poor is now deep in debt. Still, it's a good excuse for a "firecrotch" #tbt.