Ex-nice person here. It will take time before he realizes that all this being nice to people is not going to translate into the same for him. People take advantage of you. People take your kindness for granted. Hell, some partners will take your kindness for weakness and lose respect for you. I was that guy. Until I had enough and I decided not to let myself be that guy anymore. Now, I am only kind to those who are kind to me. It sucks because I used to be happier when I was letting people run me over. But you realize that you haven’t learned how to have/manage healthy relationships. I hope your BF realizes this before it gets too late. May I suggest gifting him “No more Mr. Nice Guy”?. It’s a great book that really puts things into perspective.