Need opinion pls

So there’s this girl friend that my bf has that I absolutely can’t stand. She was part of the reason why my boyfriend and I broke up for a brief time. It’s been 4 months since we got got back together after that incident but the girl friend still triggers me. I cannot stand her and I hate when my bf even talks to her anymore. She was part of the reason our relationship got fucked up in the first place. He claims he doesn’t talk to her but still feels the need to like her posts on IG. I got angry over him “liking” her photo Bc I have mentioned multiple times how I hate her, I’ve cried about her, even when I see her I still get the traumatic feelings of my break up. It just hurts because I have told my bf multiple times how I feel about this girl yet he still likes her pix. When I brought it up, he got angry at me and mentioned that he still feels the need to like her photos because that’s his friend, even tho I’m his gf that’s been really hurt by the two of them. I just find it disrespectful but maybe that’s just me, I don’t know if I’m wrong or right for being upset, but he basically told me he won’t stop liking a friend’s pictures. I don’t care if he likes other friend’s pix but it’s this specific one that triggers the fuck out of me & him liking her pic and still giving her that attention pissed me the fuck off.

He’s also only known her for less than a year, so I don’t understand why the fuck she’s so important to him still. And when I get angry he throws in my face that he had great times with her and still considers her his friend even tho we fucking broke up over them two.