Does sexual fidelity matter?

I suppose it depends on how it would affect your partner. If they would be deeply hurt then it matters.

If you have taken another human being (covers most things methinks) to be your significant other (perhaps even in some sort of ceremony) then I think the basic idea is that you are supposed to stay faithfull and certainly not cause any deliberate pain or upset. So yes, sexual fidelity is important. I also think - having seen the damage such things can cause - that just having some sort of private flirtation that is verbally intimate i.e. the sharing of secrets that exculdes your partner - is venturing on dangerous ground.
The old - can I tell my OH what we have been doing or talking about and know it won't upset him? - is a good guide line.

Absolutely, I think those who say it does not are either very naive, or very selfish/insensitive.

It is to me.

Fidelity is the cornerstone of society's stability; so yes, it matters a great deal.

As a SW I saw the misery that indfidelity causes for partners and children.

The only situation where it is acceptable is when the partners have agreed to an open marriage/partnership.

To me it is very important. I believe in trust and love.Anything else would not suit me.

It matters to me. It didn't seem to matter to my ex.
I know it matters to the present Mr A.

I believe Jerry Hall said about husband Mick's many indiscretions "it just causes chaos" I think that comment is very apt. I don't know what people mean by "open relationship" why be in a relationship at all if you can't commit. I think fidelity is very important.

YES

I've only known one couple where the 'open relationship' was a concept both wanted, and not just one 'enforcing' it on the other.

Yes, it does matter, otherwise what is there to distinguish a sexual relationship from a mere friendship or acquaintanceship?

In answer to the question, an emphatic Yes. Of course it matters, assuming there is love, respect, morals, ethics and loyalty between the two people concerned.
I think HildaW has the right idea and the litmus test she highlights is a good guideline. I guess if we do not believe that sexual fidelity is important then perhaps we should not marry or co-habit with anyone who does as that is just cruel and hurtful should the opportunity and decision ever be taken to have a 'fling'.
For my part I find the idea abhorrent and beneath contempt but each to their own. I do not expect everyone to have similar values to me but I would expect honesty. As a victim of infidelity I would not encourage the act.

I think probably we are brought up to think that sexual relationships should be exclusive and the concept of fidelity is very much culturally determined.

Having said that, personally I would feel very insecure in an "open" relationship.

Everyone posting seems to assume that I was talking about an "open" marriage/partnership. One person in a partnership can be sexually unfaithful without telling the other. So is it true that what you don't know, can't hurt you? Of course, not all infidelity is mainly sexual. I know of a woman who discovered that her husband was being unfaithful because she realised that someone was darning his socks. How romantic is that?

If you DON'T know it can't hurt you - except your relationship is a lie, even if you aren't aware of that at the moment.

How can you have a true loving relationship if one of you is hiding the fact that he/she is also "in a relationship" with someone else. You are not then being honest with the person you say you love.

Eventually the truth is likely to come out, which would undoubtedly hurt your partner very much.

I'm sure I remember reading an article a couple of years ago (I think by Katherine Whitehorn) which suggested that it was a trend for middle aged/elderly women to find lovers because they were fed up with routine or non-existent sex with their husbands.

I think there is a lot of 'well, my partner will never know' thinking involved, but in fact the truth often outs. One man I knew who had a series of affairs was involved in a car crash when driving one of his lovers. His wife was called to the hospital and was told that there was another person in the car. She soon worked out the truth - there was no reason for him to be where he was, or to have the other woman with him.
Another danger is that the lover might get jealous/vindictive and inform the other partner. I think this is why some people prefer to take married lovers - on the basis that they will have an equal amount to lose.

I think sexual fidelity is an indication of the strength of the bond between two people. If the bond is weak, one or both may start to look around. And once 'looking around' starts, the signal of availablility (or "maybe availability") is picked up by others who are looking around.

So I think sexual fidelity is great where it exists, but not 'wrong' where it doesn't. We're only human. We're only animals. In a way, I find it surprising that so many people have such a strong bond with their partner to the sexual exclusion of everyone else. Surprising and wonderful.

I had a long discussion with my daughter and her husband about this and they both said that it was quite natural to be attracted to sombody else, but if you loved your partner you would not act upon it. The bible takes a different view 'If a man looks after a woman so as to lust after her in his heart, he has already committed adultery'. Matthew 5.28.

For myself, I would never have stayed with a man who was unfaithful, because I would think he was stupid to choose to be with somebody else when he could be with me!

Honesty is the key - if you have made a promise to be faithful to one person then you should stick to that. If you decide to break the promise, you should tell your partner.

Think it essential to a loving relationship to adhere to fidelity .

I totally agree with Ganjura on this: "Absolutely, I think those who say it does not are either very naive, or very selfish/insensitive."

If you have a good marriage/relationship you would never cheat on your partner and, yes, I do believe it is cheating. I can't even keep a secret from DH, I am finding it terribly hard to keep one at the moment which is simply a lovely surprise for him.

On the other hand, sexual fidelity does not necessarily indicate a loving relationship

Before we married my DH and I agreed there would be no second chances, if one or the other strayed that would be the end of the marriage. As a result we had complete trust in each other - I never met anyone who was more attractive to me than my DH and I know he was faithful to me because he said if ever he met anyone he was more attracted to he would tell me before he told her!