she was a bit drunk a few nights ago and told me that she wants to see me fight for her in some way. I know that I am - but I think she needs to know it, and there's no way to really fight for her without fighting against her, is there?
Wow! That sounds familiar. Good luck with this one. I think it circles back to the original issue that caused me to chime in (see above). I'm interested to hear what more accomplished DB'ers have to say on this point, because I don't think the books really cover this "fight for me" situation.
I will say it again at the risk of unintentionally inviting a lot of angry replies, but I think the standard DB approach comes off as too passive and weak for some walk-away spouses, especially ones that, despite their intelligence, harbor immature, cartoonish notions of what it means to "fight for" someone.
I mean, really, what does she want you to do, kick the guy's ass? Maybe you should simply and sincerely ask her, "What do you mean, you want me to 'fight' for you? Give me examples."
Also, for what it's worth, while you (and everyone else on these boards) can endlessly try to imagine what might have happened if you had never vocalized your boundary, my (admittedly amateur) opinion from reading your situation is that if you hadn't established a reasonable boundary by saying you can't tolerate living under the same roof while she runs off to "explore" with the OM, then your wife might only use this perceived (but not actual) passivity as yet more fuel for the "you just don't care about me" fire!
I can't remember whether you explained the details of your boundary. Did you tell her "we're through" if she goes on the trip with OM, or did you simply tell her you were going to remove yourself from the situation, which without more only suggests you're going to live separately during this experimental phase? I'm not sure you lose much consistency if it's the former and you now tell her that after much serious thought you've decided that you aren't going to immediately seek divorce if she goes on the trip with OM, but you are going to remove yourself through a trial separation--one that is both physical and financial.