My best friend in the world has been dating a girl who is terrible to him. Yells at him in public, causes scenes, belittles him, etc. I have told him on several occasions in the past that I don’t think he’s in a good relationship and that he should end it. He’s an extremely nice guy who always finds an excuse for it though and he’s stuck it out. He just told me and another mutual friend that he proposed last night. He was excited and asked me to be in his wedding today but I said no. I feel like that position means you are the type of person with the grooms best interests in mind and I just can’t support it. He was upset but is still a nice guy however I think I might have just ended our friendship.