He Liked A Girls Thong Picture On Instagram

So my bf and I r (16 and 18). Throughout our relationship he’s always liked photos on ig of Girls in bikinis or half naked pics. He doesn’t even know these girls. He just likes these random girls photos. I told him a long time ago I didn’t like it cause i think it’s disrespectful to me and I asked him if he could stop. He still never rlly stopped doing it! For a while I didn’t see him do it but today a girl posted a full out thong pic and who do I see that liked it? My boyfriend. Again. This rlly annoys me cause he doesn’t like when I post pics that r “too revealing” so I don’t do that. But he’s aloud to do whatever he wants. Idk what to do. Should I talk to him about it or leave it alone?