Ghost0007, I don’t know if you’re still reading this thread, but believe me, I really feel for you. Your posts are some of the best I have ever seen, and I’d like to help you.
You were asking why this happened.
Obviously, even with the thorough posts, I don’t know the complete situation. What I can tell you is the following, which may or may not shed light. Please note that I am neither blaming you nor your ex-wife. What I describe below is the result of human nature and social conditioning. (Please note my comments are based on the red pill theory - see reddit).
First, with regard to why she cheated, couple of hypotheses.
I take it you were incredibly nice to your wife, put her on a pedestal, and treated her “like she is the most special woman on earth.” Unfortunately, women are biologically programmed to be attracted to men who are “better” than them (taller, more educated, stronger, etc.). I’m not making a normative statement, just stating a biological fact. Being treated well is OK, but if they’re treated like a princess then subconsciously, they are programmed to feel that the man doesn’t deserve her. Women say they want to be treated like a princess but as you can tell by the fact that many women like bad boys more than nice guys, what they say and do are not always the same.
Second, it sounds like you spent a lot of time talking with her. It’s OK for her to share her feelings with you, but did you share your feelings with her? Any worries, insecurities, weaknesses? Once again, women ask for you to share you feelings but the main reason is to sniff out weaknesses. Sharing feelings with her, especially ones that make you sound weak or worried will kill attraction for you. Biologically, women are programmed to flee from weak men, and men who share their feelings usually fall into that category.
Once again neither of the above is your fault. What I am saying is opposite of what most of us are taught so no foul on you. It’s just that what we are taught is wrong.
And neither of the above is your ex-wife’s fault. She didn’t do it consciously. It’s just millions of years of evolution at work.
You said you were often approached by women. Did you tell her about them? If she knew that you were being approached by women on a regular basis, that would have made her less likely to cheat, because she would know you have as many or more options than she does.
Finally, in a work environment, the CEO is king. Regardless of how he looks, he has power, and power is an aphrodisiac. This may be why your wife cheated on you with him.
Clearly though she made a grievous error, not just morally but biologically. She thought that you were weak because you treated her so well, but you were strong. She thought that the CEO was more powerful and attractive than you because she spent all day at work but in the real world, the opposite was true. She thought that she had more options and could play around and you would have to accept it but the opposite was true.
I am so impressed by how you handled this. I know what I just said may sound odd, but I hope you might test it out in your next long term relationship and see if they turn out to be right.