My Boyfriend doesn’t post me

So me and my bf have been together for a year now but it’s always an issue when I️ talk about posting me on his Instagram or Snapchat . When I️ bring it up he always says well I’m not that type of guy and gets mad at me but I️ don’t know what to think. I️m not a dumb gf but I️ know he’s not cheating. So why doesn’t he want to post me? And it bothers me because I️ want to be shown off and I’ve tried to tell him how I️ feel but he doesn’t understand.