This may be longer than the allotted characters. Almost six months ago, my bf and I got into a big argument with him liking a lot of pictures on IG of girls mostly showing off their bodies. I see it as disrespectful and I myself can't even like pictures of men because it makes me feel uncomfortable
Do not take it personally. You are desirable and your BF is attracted to you. Its important to understand that males do not mature as fast as females. You therefore have a perspective that he may not share until he "grows up". Your relationship may not be the perfect match that you desire but enjoy your time together and see where it goes. You can't change him but he may grow out of it over time. Do not make him feel he has to be secretive and hide it from you because that will just plant the seeds for a bad relationship.