Kyle Richards' separation from her estranged husband, Mauricio Umansky, is clearly weighing on her -- 'cause she was reduced to tears talking about it at BravoCon.

The "Real Housewives of Beverly Hills" star was onstage Sunday in Vegas, where she was doing a Q&A ... and where she was eventually asked point blank, where do things stand between her and Mauricio right now?

The question got her quite emotional. As reported by our sister site, TooFab, Kyle first said she and Mauricio were trying to navigate this as best they could -- explaining ... "We love each other very much and we are family no matter what happens. My three girls still live at home, only Farrah has her own place. [Mauricio] was busy doing 'Dancing with the Stars,' so he wasn't around as much. We’re trying to figure it out. We know we love each other."

KR then started to choke up, saying she hears everyone telling her to just "fix" the problem -- but as she clearly states here, it's not nearly as simple as it sounds.

Of course, this comes on the heels of Kyle's other interview last night at BravoCon -- where she referred to their separation as an outright divorce ... a slip of the tongue, it seems.

From what we can gather ... things are rocky between the couple at the moment, and while it sounds like she and Mauricio might want to reconcile -- there are obstacles that stand in their way ... even as they continue to live under the same roof and film for 'RHOBH.'

That's something Kyle addressed Sunday too ... saying she didn't want her fights with Mauricio caught on camera, and that Bravo producers noticed something was off.

Adding an extra layer of complexity is the fact that Mauricio continues to get cozy with his 'DWTS' partner, Emma Slater, with whom he was again spotted at dinner this weekend.

Remember, this follows a pretty public outing the two of them shared a couple weeks ago -- where they were seen holding hands -- but people in his world tried explaining it away as merely platonic ... even though Kyle isn't buying it, and found the whole thing disrespectful.