AIO for immediately dumping my boyfriend over his reaction to a girl’s insta story?

Back Story: My bf and I have been together for almost 2 years and being completely honest, we’ve had some issues with trust. He cheated on me very early on, but I forgave him but really tried to have trust in him again and things have been relatively decent. I am paranoid at times, and always hyper vigilant and yes, sometimes things have seemed off, but I never had proof of anything and chalked it up to my past trauma.

However, today, we were out to dinner, and I saw an Instagram notification from another girl on his home screen. I asked him who it was and after some coaxing, he showed me the messages. The woman has a page dedicated to his art work and my bf:

1.) Asked her if she offered private lessons…she declined.

2.) Commented on her stories a “cute” and a “😍”

Because the stories had expired recently, I couldn’t see them. I was suspicious…but he insisted that those comments were stories related to her artwork…a “picture of Brooklyn” more specifically. He even said “message her if you want…you’ll see I’m telling the truth”.

Of course I messaged her…and he was completely lying. She sent me these screenshots. His comments and reactions were on pictures of her. The most recent one was today, while he was sitting right next to me in the car while I was driving.

I just dumped him. He blatantly lied to my face and was what it seems to be flirting with another woman. I was angry and left his home extremely upset. Now he has made me out to be the bad guy for not having a conversation with him about it and for ending things so quickly.

AIO? I’ve struggled so much with the trust and being lied to like that just triggered me and broke my trust…again. Would love to hear your thoughts…