Thought experiment for long-term partners

So lately I've been thinking about a million things involving long-term relationships like marriage. Fidelity. Attraction. Suitability. Monogamy. Avoidance. Denial. Rashness. The whole sticky, prickly, endlessly variable, endlessly fascinating damned if you do, damned if you don't, and what-the-heck-is-it-then-ness of the wide, broad middle.

My partner was on the phone for hours with an old friend from her home town tonight. Afterwards she mentioned the problems her friend has with her husband (who suffers from a permanent brain injury) and about a man she's been having a long-term affair with. My partner said "he's really been there for her all these years, he really cares for her." And then added "of course it's weird that they're both married to other people."

I could (and someday might) post about the whole new MILF phenomenon that for better or worse has given society permission to regard older, often married women as sexual beings instead of out of sight / out of mind genderless Harriets and helpmeets. Or about the implications of FILFs, a corresponding term VS has coined that demotes/promotes oder men into objects of pure desire (rather than as the more traditional sugar-daddy/seducer/Humbert-Humbert/mentor/mark roles usually assigned to men.) I could post about the evidently enormous percentage of married men who evidently haunt online dating sites. I could talk about TheGirl's guidelines for chatting up a man or chatting up a woman, both of which begin with "Check for wedding ring... check for tan-line of removed ring..." I could post about the bloggers who are conducting successful affairs, those bitter from affairs of their partners, those bitter about their marriages, those single and concerned about their married partners who are having affairs with them, those who avoid married partners, those who prefer married partners, those who are indifferent, those who worry they're wearing out their one partner, and those who can't imagine why one would settle for one in the first place. I could post about whether the traditional/biblical/patriarchial prohibitions on adultery have the same meaning in the face of birth control. And I could post endlessly about whether fidelity and monogamy are identical, overlapping, or unrelated, about whether and where on the faithfulness gradient one could place cybersex, pornography, flirting, masturbation, heavy and light petting, commitment to work, commitment to friends, etc. And one of these days I have to post about whether demanding monogamy in a sexless marriage constitutes imposing an involuntary sexual preference/orientation (asexuality) on an unwilling partner.

Someday, maybe all of the above.

For now I've got a couple of questions that comprise a little thought experiment about our own relationships (for those of us in them.)

1) How would your relationship be different if you and your partner were married to other people?

2) If you were married to someone else and then met your current partner how would you react?

I've found those are good, hard, clarifying questions. (If you think they're easy I think you'll still find them satisfyingly productive to ponder further.) They've clarified my feelings for my partner even as they've complicated my feelings about monogamy.

I'm going to go against type (I rarely answer my own questions) and say that I think my partner and I might be better off in a way if we were married to other people because our only conflicts are over domestic issues (e.g. should we fix/replace/replant/remodel this or that, should we spend hours cleaning a messy house or avoid making messes in the first place, etc.) And I believe if I met her today I'd say, as I said the first time I saw her, "where has she been my whole life?"

The upshot is it's certain that marital status would not interfere with my desire for my partner, but it undermines my committment to monogamy in the sense that I would readily (if guiltily) be unfaithful to be with her and it wouldn't trouble me if she remained in a primary relationship if that's what it took to be with her. But then if monogamy would not be important to my committment to her then where do the tempations of casual sex fit in? Which, ultimately, leads back the list of potential posts enumerated above.

#@$*%!!!

I suppose I should have titled this post "The Libertine Prude Asks" :-) Your answers to the question and analysis of mine are more than welcome.