Exactly. (Now, why didn’t I put that in the post, because those are precisely the terms I’ve always used?)

Though I would say that “mutual infidelity” is not infidelity, because there is not the breaking of the promises. When it’s mutually agreed upon, I term it “non-monogamy”.

I completely agree that it’s the betrayal that’s the root issue in the other person’s response. Which only supports my argument that perhaps what we need to do is acknowledge up front it can happen. You can decide how you deal with it should it happen — do you want to know? can you agree on parameters on the outside activities (as the couple I know who experimented with non-monogamy did)?

And you’re quite right: the initial conversation itself could be almost a deal-breaker, and undermine trust to a dangerous degree.

I don’t agree that opportunism requires many preliminary steps, however. I heard a tale (through a mutual friend who knew her) of a woman who sat beside an attractive fellow on a four-hour train trip and ended up having sex with him before she went home. (A female opportunist! They do exist!) There was no planning, no set-up, no follow-up, either. This can happen — the only prerequisite being you having a mind to let it.

I’m not claiming this issue is simple, and I’ve certainly not thought it out to a point that fully satisfies me, but the issue does roll around in my brain from time to time!

Florinda: You describe your ex-h’s affair and the subsequent fall-out so well. So much I can relate to is contained in those few lines.

You’re right: it’s not simple, it’s not black-and-white.

I do think that the male approach to this is, generally, less weighted than the female. If women responded to opportunity the way men did, we would (perhaps) be less threatened/hurt/betrayed by outside activity when he did it — because we’d understand the pull of it, and understand what it isn’t.

‘Course, there is the stepping out that’s simple opportunism, a fleeting attraction followed by a pleasurable event, and then there’s the stepping out that’s the symtom of a root issue in the relationship.

If you don’t deal with the root issues, then the relationship will almost certainly founder.

The irony here, I think, is that arranging total fidelity, and arranging mutually-satisfactory non-monogamy BOTH require commitment to the home relationship, communication, trust, and integrity.

“If infidelity is an automatic deal-breaker, then yes, the marriage will end. If both parties knew that going in, then the party who stepped out is a fool — or wants the marriage to end.

But why would you set yourselves up for that? Why make it a deal-breaker?”

In the case of my first marriage, it was stated very early on in the relationship by my (then) boyfriend that as far as he was concerned, it WOULD indeed be a deal-breaker for him. Hence, the irony when after 15 years of marriage, HE was the one who “broke” it.

My understanding of our terms was that if he was straying, it was because he wanted out. The complication was that he wasn’t so clear on that, and it was a very painful couple of years of unraveling from that point on.

The thing is, I still do believe the infidelity was a response to other issues we had (but clearly weren’t dealing with), and in itself I don’t think it WAS a deal-breaker. It just stirred up too many other things we couldn’t - or perhaps by then didn’t want to - resolve in ways that would keep the marriage together.

He’s now married to the woman he strayed with, and if I were her I’d never be sure he wouldn’t do it again. And having been there once, I do believe it WOULD be a deal-breaker in my second marriage. (And my husband is well aware of that.)

But I don’t think people who haven’t been there, one way or another, realize just how much this isn’t a black-and-white question, and that’s why I keep thinking about what you’ve said here.

It’s a bit of a catch-22 because to tell your partner that you’re attracted to other people or are craving some kind of connection outside the relationship requires such a deep level of trust, and most people who stray, I think, do so because that level of communication isn’t open to them–either because they don’t think their partner will be receptive or they themselves can’t be honest enough to express their needs.

Even in an open relationship, honesty and trust are key to keeping the primary relationship healthy, so I tend to see infidelity (the non-mutual kind) as a symptom rather than a cause. I don’t see that most people are opportunists, though. Some are, certainly, but there are usually a lot of steps to get to the point where opportunity presents itself, so I don’t buy that as an excuse.