Sorry you’re having to deal with this. It’s one of the worst things in life to experience.
Having been in your shoes before, I can share some insight that I have experienced having been in a very similar situation.
For comparison, my wife’s affair wasn’t a co-worker but a member of a hobby group she belonged to. He was a predatory mentor whom he assigned himself to my wife to help learn about beekeeping.
my wife violated boundaries, and willingly participated in flirty, innuendo laden, and sometimes sexual text exchanges with this man.
I found out by asking a question of my wife back in 2017 and the answer I got drastically changed my life. She initially stated that she ended contact with the man because he couldn’t keep the text exchanges they were having at an appropriate level. I later found out that she was more than a victim of his text based advances. She eventually admitted to feeding into the conversations as a form of manipulation because she enjoyed the attention.
There were many denials, and opportunities for physical activity which she still denies occurred to this day.
Having said all that, I have observed a few things I felt were clouded by my initial feelings of betrayal. For starters, she could have kept it secret and took the relationship (or whatever you want to call it) to the grave. She chose not to, most likely for selfish reasons to rid herself of giult. In your case as I understand it, your wife confessed without confrontation. I see that as a good thing.
Second, my wife was less than forthcoming with details I sought so I could get a better understanding of their relationship. My wife claims to have had no feelings for the person but the attention she was getting. From what you’ve posted, it appears your wife shared with you high level details around what was exchanged, and unlike my wife I needed to ultimately find some older texts to call her out on her deceit before getting enough information to comprehend the gist of it all.
Third, at some point, many months after she turned my life upside down, I felt my wife finally understood The gravity of the situation, and started to really work on herself to get a better understanding of why she would feel the need for such attention. She took the time and put in countless hours of 1:1 counseling to understand she has a lot of issues that needed to be brought to the surface and discussed to understand what in her led to the complete disregard for people other than herself.
I see there’s hope for you provided your wife continues to be completely open, honest, and transparent. In my wife’s case, it took a lot of time of 1:1 counseling for her to comprehend the damage she was doing by feeling she needed to protect herself by keeping secrets.
We are two years out from the day my wife shared the initial conversation, it’s been a very rocky road until the past 6 or 8 months.
I have undergone 1:1 counseling myself and it has helped immensely. Something I wish I had done many years ago but let myself down by making up excuses to not do it.
We’re healthier now, I am still scarred and often trust but verify when I get a hunch or gut feel when something doesn’t feel right.
Wishing you the very best.