Tanning Mom -- A Wasted, Stumbling, Panty-Flashing Train Wreck [VIDEO]

Tanning Mom Patricia Krentcil could barely stay upright last night at a gay NYC nightclub -- stumbling all over the place, laughing hysterically, flashing her panties ... and it was all caught on tape.

Seriously, words can't describe how wasted she was -- in fact, the 44-year-old mother was so messed up ... she had to be escorted off the stage because she kept trying to snatch the MC's mic away.

It's really awkward. The guy's expression says it all.

Krentcil had been invited to the midtown XL Nightclub to host the weekly "Hot Mess" party -- appropriately named -- but her hosting duties were cut short because she was so out of it.

You'll recall, Tanning Mom was charged with child endangerment earlier this year after allegedly bringing her daughter to a tanning salon. She pled not guilty.