He still thinks about his ex?

My boyfriend and I have been together for a year now, but before we dated he dated another girl (we’ll call her Alex). He dated Alex for almost a year and she was his first love. He was in love with her and when they broke up he was really hurt by it. It’s been over 2 years since they’ve broke up, but I’ve seen him looking at her insta twice now. He’s still checking his ex’s social media. Am I crazy for being concerned? Should i talk to him about it?