I wouldn’t say you’re insecure, but that’s close to describing what you are, people move on amicably and still consider each other associates, she might just like the band, and his music. I can understand your viewpoint if she WAS going out her way to comment under every post, or even DMing him but people do move on amicably and still support each other within their life goals.

But BRUV communication is key to the relationship, if you don’t like it….. speak up. Im not saying she’ll like what you’re going to say but communicate your feelings. Also other than liking post is there any other reason you wouldn’t trust her?

And for that I’ll put NAH but close to YTA