Kristin Cavallari's clearly living her best life ... moving, grooving and pouring booze at a gay bar after telling her fans she's got no interest in running back to her exes for anything more than sex.

The reality star-turned-social media influencer hit up Flaming Saddles -- a hot spot in Manhattan -- Thursday night ... and, while she didn't ride any horses, she went for a twirl on the bar and showed off her best dance moves on the bar top.

Check out the clip ... Kristin shakes her booty while dropping it to the floor -- or, in this case, the bar -- before picking up a bottle of alcohol and spreading the wealth among several enthusiastic customers.

She pours liquor straight into a couple waiting mouths before the clip ends ... and, it shows just how much fun KC's having in her single life.

As we told you ... Kristin says she's embracing her life as an independent woman -- adding she's not pining for any of her exes.

She did admit during a recent podcast taping that if she absolutely had to pick an ex to get back with it would be Mark Estes -- 'cause she knows he'd give her the right kind of lovin'.

Bottom line ... Kristin's clearly not sitting at home crying over a past flame -- 'cause she'd rather be partying at Flaming Saddles instead!