Well, I am only open to the idea of a secondary thing with another woman at this time. She need not have any sexual contact with Zen, nor even need to be comfortable with him watching (I refuse to make unicorn hunters of us) but if she wanted to initiate a situation of involvement with both of us, we might go with it and it might be alright. She does have to be socially comfortable with him. Anyone who makes him feel "shut out" when we are all social together, is going to make me uncomfortable. I don't want to feel pulled two ways.
Like a good barometer of that, is if she can give him a hello/goodbye hug in a social situation and appear comfortable about it, then we're probably ok.
I'm too deeply invested in my thing with Zen to put up with awkwardness or keep things completely compartmentalized.
I don't do closets. I don't keep secrets unless specifically asked. I'm out and open as the day is long. I love PDA...if I feel treated as a "just friend" then that's what we will be, and that is ok! If we're more...treat me as more. Hell, I'm very physically affectionate with even my "just friends" so I kind of need and expect that.
Any partner of mine in the future has to be able to go to BDSM events with me. It's a huge part of my life. I'm likely to find partners within that community anyways, if I'm apt to find them anywhere. They (in the case of a secondary female partner) do not have to be in any particular role, I could be fine with a Domme, a sub, a switch, a sadist or masochist, top or bottom or Mistress or slave...although I don't think that I have the bandwidth to do a serious 24/7 power dynamic with someone, so they'd have to not need that from me (it's fine if they're getting that with someone else though.)
I have to know they are not cheating on any other partners in their life, without a doubt. This is most easily accomplished by me having a conversation with my meta(s.) But in the case of Fire, who had other partners I never met, I felt very confident that they knew she was married and had others, that none of them thought that they were her one and only. I trusted her ethics. But if someone says they are in a DADT and their partner gets very limited knowledge of other partners...that's gonna be a no-go for me.
Other than that, it's going to be how well they fit with my life and general compatibility. I don't mind being supportive of one who has some issues (I mean, don't we all?) but I cannot feel overburdened or taken advantage of. I have a realistic idea of how much I have to give before the scales tip and I can't meet obligations...so I do tend to rule out people who have very serious disabilities where they are seeking a caregiver, small children, serious drug addictions, major financial crisis... I have to look at how heavily someone is going to lean on me and whether I can bear it and still hold up everything else I need to. And given the limits on my bandwidth right now, I'm thinking the most I could promise any secondary would be FWB sort of thing anyways...but all of the above considerations, still apply.
I know it probably limits my prospects rather severely, but I'd rather have no secondary, than a problematic secondary.