Relationship Advice ASAP

So, i need some quick advice. Me and my boyfriend have been together for a year already, & soon to be parents as well. Had a few ups and downs in the beginning but got I️t all settled after we worked I️t out. Recently i saw his IG and saw he liked some of his EX’s posts where she posts her body after a workout or just where you can see a good angle of her body figures. We had agreed that we would have no interaction with our past relationships meaning ex’s & so I’ve committed to that and no longer have anything with anyone except my boyfriend of course. Am I️ thinking this too much and making I️t a big deal or is I️t really nothing to worry about? HELP PLS!!!! My friends said that’s very disrespectful towards our relationship but I️ want to hear other advice!!

Also, if I️t is a big deal should I️ bring I️t up or just let I️t go?????