Judging from this and prior posts of yours, your wife appears to be a serial adulteress. My advice would be to tell her that YOU cannot live in an open marriage, and that she should pack her stuff and leave -- now.
She's in no position to be telling YOU what to do re: separation, etc. If she wants to file, let her file. I suspect she's just trying to string this out financially, since she can't support herself right now, or she's merely trying to keep both plates spinning on the sticks -- you and OM (other MEN?).
Why would you be making her nice dinners, etc., while she is out cheating on you, and she's done this before as well? To me, that sends ENTIRELY the wrong message, and I think your wife -- in all likelihood -- doesn't take you very seriously anymore.
