Wrong?

Okay, my boyfriend and I have been together for 2 years with an amazing son and he has a daughter from a previous relationship. I have an old friend, literally that I only ever talked to and never met who happens to be a guy, and he likes my IG posts and my boyfriend gets incredibly mad and upset. I’ve never had anything with this guy so therefore I’m not in the wrong because he’s taking everything the wrong way. Right? Hes never even caused issues in our relationship or anything like that I don’t get it.