Any time this has come up over the past couple months she vehemently denies ever cheating in any way...but of course I can't know for sure.
For those who haven't made a study of infidelity like many of us here through trying to untangle what the heck happened, most people have a very specific definition of what constitutes and "affair". Just ask Bill Clinton (sorry if I offended anyone's politics).
Emotional affairs / fantasy affairs can be just as damaging and sometimes more than when people get down and dirty doing the horizontal mambo. More so when both people are heavily invested in it. After all, our marriages weren't just about sex - heck for many of us who were married for a long time sex wasn't even all that frequent.
BUT - she probably doesn't see it as an "affair" and you can feel free to go along with that narrative. It is a huge red flag in your relationship though. I honestly don't know what to advise you as far as dealing with that goes though. I'm certainly not an expert but I hope you have ones available to you.
A few things that I've learned that are important in any marriage is openness, honest communication and recipocity. For a bunch of us here many of our marriages were pretty one-sided where either us as LBS were either carrying much of the load of the marriage or pretty much none of it. Have you given thought to how the dynamic of your own marriage and family falls into that? I'm not saying that you needed to both carry half of each load, that's unreasonable for most families, but do you think that both of you feel that the other is "doing their part"?
Just some things to think about.
On BD H52, W50 T27, M26 S21, D23 BD-9-Mar-16 D-15-Jan-18 Final-19-Apr-18 I am a storyteller. The story may do you no good. But a story is never for the listener. It is always for the one who tells