But hell, what do you do as a friend? How can you watch someone you honestly love do something you feel will hurt them without saying something?
Being friends is great, but I don't think you can be *that* friend to your W. As you know, she's going to do whatever she wants. All you're doing is going on record, and if OM does end up hurting her, not only will she be hurt, she'll be angry at you. Not rational, of course, but she will be, because you were right. You don't get to warn her and then be there to comfort her when it all falls apart, and you're choosing the warning.
I know you're also thinking about your girls, but it doesn't change anything.
Also, you're right that moving out is going to give her a lot of physical space, but what about emotional space? If I were you, I'd back a lot further off in that department. Obviously I'm focusing on just the last couple of conversations you've described, and you have more interactions with her than that. You say you feel different and she can tell, but FWIW, I'd bite my tongue anytime I felt the urge to say something that started with, "I'm telling you this as a friend." You can't give her space and be that friend, too. Let someone else be that friend---you be the friend that helps her when she asks for it.
