How would you feel?

If he follows his ex on socials (never married or kids) he says cheated on him and broke up almost 2 years ago, would you have concerns as to why they’re still connected?? I haven’t said anything but it kinda raises a flag to me, I’ve noted she left a comment a few months on one of his posts calling him a nickname followed by a heart eye emoji and him liking it in the early stages of us. Starting to think him saying she cheated isn’t the full story? And I feel confronting this he’ll think I’m some crazy bitch …like no, I just don’t want to be wasting my time.