The supermodel capped off her Aspen weekend Sunday by hitting up one of the hot spots there in town, Catch, and we gotta say ... she looked damn good walking into the joint, rocking a very on-theme black and white ensemble that she was wearing the hell out of.

Now, KJ was fairly stone-faced ... not revealing any emotion, one way or another, that you could attach to her new relationship status.

Couple ways to interpret that, we suppose -- either she's somber/sad about the split, or doesn't have a care in the world. Eye of the beholder, as they say.

Anyway, Justin and Hailey Bieber joined her to chow down ... they were also there in Aspen, and we know they're already great friends. Them joining could just be pals getting together for dinner ... or a coming-together of consolation. Either way, they had her back.

Of course, them breaking bread -- very publicly, mind you -- comes on the heels of word that Kendall and Bad Bunny split ... this after not being seen together for well over a month.

The last time they were pictured together was actually in a photo we obtained ... the morning after their big Halloween bash in late October, where they were grabbing breakfast together and looking very much so like a couple. Since then, they've noticeably been apart.

Kendall did allude to a potential breakup back in mid-November ... when she threw up a cryptic IG post that said whatever was meant for her would find its way to her.

BB, meanwhile, hasn't said diddly squat ... and he's laid pretty low heading into November/December. If they are, in fact, dunzo as reports claim -- they had a good run.