Several years ago I found out that my H had had a drunken one night stand over 10 years previously (no sex, too drunk, but intention there). We spent 6 months trying to deal with it and then 18 months with Relate. Throughout this period he was clear that he wanted to be with me.
Finally, after yet another row when he said I wouldn't let the one-night stand go, I realised it was him that kept bringing it up not me.
Turned out that he came back from it and thought 'If my relationship was fantastic I wouldn't be looking elsewhere. I looked elsewhere, therefore my relationship isn't fantastic'. And by relationship, obviously, he meant me. And from there on he slowly but surely undermined the both the relationship and me.
It's easy to see things with hindsight but once I knew about it I could pinpoint the trip where the one-night stand happened. Given it was over 10 years previously, I have a crap memory, and he did a fair few business trips, I was clearly aware on some subconscious level that something had shifted fundamentally.
The irony is that I don't see infidelity as necessarily a deal breaker (and actually he knew that). Had he told me I'd probably have been very angry to start with but also probably taken the piss mercilessly at his complete failure to actually have sex! I think that he didn't tell me because, had it been the other way round, he wouldn't have forgiven me.
For me, the great betrayal has been the secret which has undermined our relationship and how he sees me. It proved almost impossible for me to get past feeling that most of our relationship was a lie but I would have done it if he?d shown he was truly committed to being with me. Now we have separated and I have found some perspective. Read anything Whenwillifeelnormal has written about how men who have affairs behave ? that?s what my H did but over years and years and without an OW!
I wouldn?t presume to tell you what you should or shouldn?t do, only you know your relationship. The point I am making is even trivial incidents which, in theory, can be compartmentalised, can have completely unexpected and unforeseen consequences.
Oh, and for those who think they know their DHs, mine was absolutely crap at lying (or so I thought!).