AITA for cutting ties with one roommate and dividing the house because she can't stop making comments about my girlfriend?

So, to start, I've had problems with roommates before, as you can see from my post history. I live with three people, a couple I knew for a bit before moving in (who we'll call Jon and Abby) and one single guy, Ted, who I've been friends with for a long while. Things were tense from a few months in, but mostly improved over the year, only to flair up again recently.

The problem is Abby cannot stop making racist "jokes" about my girlfriend, who is Chinese. They range from the standard dumb remarks about eating dogs and having weird accents to straight up saying that she thinks a lot of Asian people are creepy. She never says them in front of my girlfriend, and I've tried to tell her they make me uncomfortable, but I get the standard "I'm-not-a-racist-I-voted-for-Hilary-you-just-need-to-take-a-joke" response every time. All of this despite the fact that my girlfriend has been completely respectful, rarely ever stays over (like less than two weeks total over the almost one year we've all lived together) and has even treated all of us to large meals in the past (which Abby didn't even touch because she doesn't like traditional Chinese foods).

The final straw was, admittedly, a pretty small one that I reacted poorly to. When they ordered from a local sushi place (I know, ironic) and she was struggling with the chopsticks, she looked at me and said "hey, you date a lot of Asians, how do you do this?" To which I responded with a short "fuck you." When Jon said I was being rude, I pointed out that I'd made my position clear in the past and refused to apologize, and that Abby should know better than that by now. Abby started up the same "I'm-not-a-racist" argument and I told her flat out I didn't believe her, and that if she wasn't a racist she wouldn't make so many jokes or casually use the n word as a punchline (another of her and Jon's favorites.) The argument continued the rest of the night, with Ted getting dragged into it when he got home (he said he didn't think Abby was racist "in her heart" but should stop with the jokes).

It's been two months and we don't speak at all anymore (except Ted and I), despite the quarantine keeping us together. Jon and Abby are moving out two months early, and our mutual friends say that I was being openly hostile (not completely untrue) made them too uncomfortable in a difficult time (they're both essential workers, I'm in tech so I work from home) and that I'm an asshole for refusing to let a small comment fly. I feel that it's not a small comment but a lengthy buildup, and she had plenty of warning. Am I the asshole here?

EDIT 1: a quick fix about the food, and a brief defense of Ted. While his defense of Abby is pretty lackluster, something he admitted, as he feels that since he's the main point of connection between the two of us he needs to play the peacekeeper. He blew up at Abby about two days later due to something unrelated and explicitly told her that the reason he doesn't bring certain guests home is that he's afraid she'll alienate them with her remarks, which is why they don't talk with him as much anymore either.