If the cheating includes lying without permission, then the marriage might be stable but it is horribly unethical to the spouse cheated on who might leave if they knew the truth.

I agree, but you're going broad whereas I'm going narrow. "People group" was intended to convey small clusters of people like neighborhoods, instead of larger groups like nations (or ethnicities). For example an urban Californian is not from the same people group as a rural Californian. The culture (and hence cultural expectations) of a Utah Mormon couple is different from the culture of a conservative couple from the south.

Sorry. Interpersonal is correct.

It may or may not justify the conclusion, depending on what you mean by "marriage." Hardball indicates that the "marriage" was already broken before information was shared. Others probably hold that as long as they are "together" (perhaps in some legal sense) then the marriage is still there and it's the sharing that runs the possibly of ending it.

Oh, wonderful. Live a lie and sustain a loveless marriage of a sham.

Eh, if the spouse is happier without knowing then I don't think it's unethical to prevent him/her from knowing.

If they sleep with someone else the marriage is a "lie" and "loveless?" That's ridiculous.

I see. The question still remains - if it's expected that normal, healthy men cheat on their wives within a culture, but the wives still view it as a betrayal, then what? I knew a chick once whose father cheated on her mother, and who overheard her mother in a rage, yelling "how could you let me find out?!" Still together, apparently.

As long as they're happy together and both feel that their goals in the marriage are being fulfilled.

The only way you could be sure of that is if he or she specifically told you previously (which does happen) that he or she doesn't want to be told.

You could even make the case that it is ethical even if they hadn't told you that, but you are sure they would have, had they been asked.

But in real life the vast majority of people use the words you wrote as a rationalization. They have no right to take the chance that the person would have been rather been told. Of they might have rather been told because they would leave. And the cheater might not like that. So he doesn't tell and uses your excuse, when it fact his decision to remain slient was for selfish reasons.

Doesn't matter whether it's for selfish reasons. Few moral systems are based on a martyr complex.

Why would you need to be sure?

Ok. But then why even bother saying she would be happier without knowing?

Because I'm a utilitarian. Morality defined by highest degree of happiness.

Pot Odds. If you tell your wife and she would not have wanted to know, that error is not nearly as distress causing as how upset she would be to know she spent her life with a cheater if in fact she would have chosen not to.

If you disagree with that let me propose this thought experimnt. I pay a young actor to marry and pretend to love my 35 year old daughter until she dies. Have I harmed her if she never finds out? If you say no, what about if there is a small chance she would?

I'll inform a friend if they're being cheated on every time, mainly because it's the type of information I'd want in the same situation. If the friend ends up being offended by this revelation and hating me for filling him/her in on reality then that's not a person I'd care to be friends with anyway.

She tells people to turn there mobile phones off and has a naughty chair for anybody who arrives late.

Genius!... how much do these lessons cost per hour?

We are talking adults here, they know this going in, and it's probably a part of the 'charm'. Turning off phones should be standard for classes like this anyway.

I still don't get what's the big deal. You can get the same from any number of preachers in all religions. The only thing I can see that's different is her clientele of seemingly 'too sophisticated for that sort of thing' writers and artsy types who, for some reason, find her method of presentation less 'trailer park', which I hope is understood the way I mean it.

It's still The Bible and Talmud, after all, no matter how she presents it.

I'm curious to know how do you know this?
(Yes it is a serious question)

What if one must endure a period of lesser happiness to obtain a higher level of happiness? It seems that your model of happiness could easily have someone be stuck at a mere local maximum forever, and thereby ending up with a lower average happiness than what is possible.

This speaks to the idea in my previous post. What if the happiness in the marriage is higher BECAUSE she found out (in the long run) and they had to experience a period of lesser happiness to get there?

Edit: Upon a brief reflection, it is possible that the memory isn't complete, and the entire sentence was something like "How could you let me find out like THAT?" Of course, this is just speculation.

But as to your question, I believe that marriage is more about the relationship between the two people and not the cultural expectation of it, and therefore the interpersonal expectation is of greater importance than the cultural one.

Lets put aside the question of what should be done if it is unclear if she would want to know. Suppose she had previously stated in no uncertain terms that she would. Do madnak, Andy Fox and others still find ethical rationalizations to not tell her?

Why is it my responsibility to help her make a better decision when the situation had nothing to do with me in the first place but could cost me a friend?

Who said anything about a loveless marriage? You also got a little confused about the frame of reference here (we are looking at it from our perspective, not the husband's or wife's).

So what's the deal David, are you atheist or not?

Obviously, this would depend on what that chance is, wouldn't it?

Then it's correct to tell her. I don't think this situation tends to be common. If the marriage is already good, then I don't think it's likely to get better because one partner finds out the other is cheating. If the marriage is already unstable, then this kind of revelation seems likely to end it - which could be a good thing if the partners move on to better outcomes, but the reality of divorce doesn't seem so hopeful to me.

No, she was using this anecdote to illustrate that her family has a dysfunctional (from her perspective) way of looking at infidelity. Seems awfully practical to me.

I don't care what she says she wants. I care what will be the best outcome for her.