I'm a bit reluctant to respond given the direction this thread has taken, but here goes anyway. Anonymous account created because this is not a public topic for me.
I'm very happily married, for 11 years. We have a truly incredible marriage. We respect each other intellectually, we're compatible sexually, we're on the same page with finances and the kids. Approaching FI quite quickly (this is the MMM forum so let's throw that in there.) And we're really good at communication. Neither of us is the jealous type. We were close friends for over a decade before we became a couple, and so naturally we knew each other's pre-us significant others and we can still talk about previous relationships, etc. It is a very peaceful and chilled-out marriage.
So for the first 10 years of marriage, I was truly never tempted by anyone. I wondered once or twice what would happen if I were....because logically, it was going to happen at some point. And I agree with the previous poster that no matter how incredible your spouse might be, a single person can't be everything in the world.
Last August, it happened. Conference travel, met a colleague I'd met once before years ago. My reaction about knocked me over- physical, intellectual, emotional attraction of vast proportions, and in both directions. Luckily I have ironclad self control and don't believe in infidelity. Nothing happened. Came home, intended to forget all about it. But didn't forget all about it. I spent two months trying to, and mulling over the questions- What am I feeling...what is it appropriate to be feeling...what am I going to do about it anyway. Threw myself into work, threw myself into exercise every day, turned to my spouse and really focused on that connection and closeness. Lost 20 pounds from the stress + exercise.
At the same time, spouse and I were focusing on connecting and exploring our marriage...and eventually we talked about it. It took 2+ months for me to decide if I was being selfing by talking, if it would hurt my spouse to make myself feel better- I don't believe in that, either. But in this case, talking was the right decision. We are good communicators, we are not jealous, and it was not hurtful in the end. My relief was vast, and my spouse was absolutely touched by my trust to be able to talk about it.
And in our case...my spouse was exploring the concept of marriage and partnerships and what they can be. And we agreed (and it was not my idea) to explore the idea of opening our marriage. Periodically for work I fly to this colleague's city. And we generally see each other twice a year at conferences. So it has been just over a year. Twice last fall I flew there for work and we were together. Once this spring I flew there and we met for dinner with other friends because we were not both free to be with each other, and we were NOT together. And this month we met at a conference and were together.
Always with my spouse's approval and blessing.
I don't know how unusual this situation is- to me it feels very unusual because I grew up with a strict definition of monogamous marriage. And also, I don't necessarily recommend it- without excellent communication and understanding, I think something like this could go south really quickly. If I were doing it out of a place of discontentment with my marriage, to run away and escape, to try to fill a vast hole of what's missing in my life- that could go south quickly too. But we're doing this from a place of a VERY strong marriage, a very happy and peaceful marriage.
And it's been really hard at times. The difficult parts have come from my emotional attraction to my colleague. I fell rather hard, resulting in an emotional up-and-down as that relationship has come and gone over the last year. If I were chill about it, it would have prevented 95% of the resulting angst for both me and my spouse. It's something I'm working on, and still assessing if it's worth it to continue. (On the other hand, if I were chill about it, it wouldn't have happened at all....) And...it's hard because I have nobody I can trust to talk to about any of it except the two folks involved. It would be nice to have a friend to confide in.
But for us, me and my spouse, in our very specific case, it has been an adventure that I wouldn't undo. It has brought us closer. Significantly. It has made our good communication even better. It has helped me overcome some rather large inhibitions. It has made our trust in each other vast. And it's opened us to be free to discuss what we want and what can make us closer. But never in a million years did I expect we'd take our marriage in this direction.
So there's a high-level version of my story, that I've never shared anywhere. Hope it was helpful.