Trot,
IMO, the bottom line is, let them make their decision. It is their life. I know, personally, I have a very difficult time letting others butt in to my business. After all, that is what dubs do, isn't it? Be a friend to them, that is all. If they ask your opinion, offer it. I know, it hurts to say that, but, in the end, you have to let them live their life.