Don't bring it to the table
(TL;DR - My ex-wife and I had a fight before a session started, and we did a bunch of stuff during the session to continue fighting.)
In the year before finally getting divorced, my wife and I got to a point where we were fighting about almost every stupid thing near constantly.
I was running a game that was basically an ad hoc combination of D&D 3.5 and Pathfinder first edition with a few house rules, I ran it Monday and Tuesday nights, in person at my house, and I had six players including my wife.
Three years into this game, and she still didn't know her sheet, didn't really understand any of the rules, but she had an over the top unforgettable loony character, and she role-played her extremely well.
One day her and I had a huge fight about money. At the time I was working for a garbage collection company, she wasn't working at all, and she could not understand why I was making $30,000 a year and we were still struggling. I tried explaining to her that $30k per year is not very much, and it was just getting our bills paid. She straight up accused me of having some kind of expensive drug problem, or financing a secret family. We fight about this for most of the day.
We put our son to bed, the players came over, we sit down to play, and I pick back up where we had left off.
The party had been lodged at an inn while picking up side quests to keep themselves busy until a major plot event happened, and the session was going to be mostly devoted to item creation, shopping and general antics.
At one point my wife's character and the party fighter were in a shop while the fighter was trying to negotiate purchasing a magic weapon. During the role-play, the shopkeeper says that the markup on the weapon in question was not much, and that he definitely wasn't getting rich on it for the price he was charging.
My wife then pipes up-
"I bet he didn't really pay much for it and he's just shoveling money into his other family."
The way she said it was incredibly snarky and passive aggressive. I tried to ignore it and move on.
Throughout that one interaction there, she continued to make a few other jabs like that before the party fighter and the merchant came to an agreement.
I went to the party sorcerer who was working on trying to gather material components to be able to craft an item. Again my wife chimes in-
"Those aren't that expensive. None of it adds up to 30,000 gold."
I told her to knock it off and we continued to work at the price list and talk about availability. She would make another couple of quips about only being able to afford certain components when it was convenient for the shopkeeper and other such things. Finally I lost my cool and made a jab-
"Yeah? Well maybe the shopkeeper would have the extra for better components if his wife wouldn't keep spending it on stupid shit!"
"Maybe the shopkeeper should actually be honest with what he's doing with it!"
"How much more honest is overhead and upkeep?! If she would actually draw an income of her own and help him out, maybe they wouldn't be struggling so much!"
At this point the rest of the table became very quiet, fully realizing that this was something that we had been fighting about all day and, apparently, were not willing to let go.
After about a half-hour of that, the players excused themselves and went home. And my wife and I continued to fight about money for the rest of the night.
That group basically fragmented in three when my wife and I finally got divorced. She got a group with her cousin and her cousin's boyfriend; I got to keep my two friends, and I ultimately had to kick our roommate for something unrelated.