AITAH for correcting an acquaintances gross/rude behavior?
While visiting a friend's house one evening for some over due catching up, his bff's X girlfriend decided to invite herself to the house knowing her X would be there. For context, their breakup was only a few months ago, very messy, and the X girlfriend is not in a good emotional space where her X is concerned. I knew that a complete $#!+ show was going to commence once she got there and drinks started flowing, so I braced for the drama. My friend (M and owner of the house) said he was all for the show. Sure enough, she came in and immediately started being snarky and dismissive towards her X, like him being there was a massive inconvenience when SHE was the one crashing. Her X is very sensitive and a bit dramatic so he left the room pouting. I my friend left to check on something, so while she and I were alone, I tried to gently, but firmly check her on her behavior so it did not escalate and ruin the night for everyone. To summarize, I told her to stop being snarky and if she couldn't keep things cordial and polite, then she should leave, since she was the last to arrive and knew her X would be there. She tried to gaslight me by denying her obviously rude behavior, but I wasn't having it. Later that night, I ordered food for everyone and she took a piece of brownie, ate 80% of the piece, then tried to put the uneaten pieces back in the box that still had a lot of uneaten brownie in it! I immediately stopped her before she could and told her that if she was not intending to finish it, then throw it away. She she accused me of yelling at her which I immediately apologized for and explained why I was repulsed by her action. Even though I apologized for snapping at her, she joked later when her X went to grab food by saying " DON'T PUT ANY HALF EATEN FOOD BACK IN THE BOX, OR OP WILL YELL AT YOU!" she then looked at me and said "just kidding". I smiled and said it was ok, because her X new better and would do that anyway. The rest of the night went ok and I went home late to sleep in my own bed. It only occurs to me now, that I may have been an a-hole since she brought it up later. So am I the Ahole?