I can only echo the recommendation to 'unfollow', it's not as aprupt as unfriending but it means you won't see their timeline posts unless you click on their profile.

I have unfollowed a couple of people who I didn't appreciate seeing their posts - nothing personal to me. In my case they weren't close at all, in your case I can see for your bf's sake you would want to check profile sometimes for family photos etc.

I too dislike those passive aggressive type vague posts - a young relative was targeted in that way and I see the pain it can cause. My advice to her was to disengage and be cautious around that person, but know that it said more about the poster than anyone else.