My advice as a grandma and having been around men all my life, dated for years until I got married now for 34 years it is clear to me that your boyfriend is moving along without you in tow, he will keep protesting that is not true to you and the fact is that he is hanging on to you until something better comes along. Get the best of the situation and dump him and you move along first. You deserve a man who is so sure of you and happy that he would take every opportunity to show you off to his friends. I married a man like that and he still calls me his "bride" to his friends.