Help With Jealousy?

I have a boyfriend and we have been dating for a little over a year now. Love him to death and we really have no relationship issues. But I am beginning to get this jealousy about him. He loves to post to /r/gaybears and sends me what he posts on there. I love the pics and I feel special thinking that I'm the only one seeing it. But then I see the same pic on there and get this awful feeling like some sort of jealousy. In my head I just say some greedy shit like "he's mine and I should be the only one allowed to see him naked." Also he doesn't really hide his posts from me and openly talks about it with me.What should I do or say about it?TL;DR: Boyfriend sends me pics I think only I'm seeing but they're shared to a gay subreddit. I get upset about it.