Brother, you have my sympathies. I have a similar situation to you, except my XWW had a thing for her AP (whom I didn't like at all and she knew it) from before we got together and he only showed her any interest when I started seeing her. Also the affair lasted all through our relationship (close to 20 years, on and off) which I found out about in the most horrible way.
We divorced because I just couldn't take it, but today we co-parent well and even date as a couple, exclusively (I think, hope).
My issue with XWW, and I believe what's eating at you, is the denial of agency. If you had known what she had been doing, would you have married her? You've had a great life with her, built wonderful memories, a family, and you should be looking forward to a great future. Unfortunately, that life was built on deceptions. She took away your choice to decide your life based on the truth.
You said it was at least 3 guys, one of whom was your best friend whom you kept in contact with over the years. I can't imagine anything as disrespectful as that...on both their parts. When you got together with this 'friend' over the years, did he and your wife have a secret laugh at your expense? Their dirty little secret? Also, what I feel you may need to address is how, when and why she was able to do whatever she did AND how, when and why it ended, if it did really end.
If she was dealing with other guys, you might need to have her explain why she chose to marry you, while having 'fun-time' with other guys. My XWW actually confessed she married me because her AP wouldn't and I was a safe, reliable choice. That, in addition to finding out how 'enthusiastically' she carried on with him while being so 'Wednesday night meatloaf' with me, was the gut punch that made me have to divorce her. It took years of therapy to get past that. Still stings sometimes though. After a while she really amped things up in the bedroom, but it's bittersweet, for obvious reasons.
Moving forward I suggest you do the following (which I didn't do) concurrently:
- Have her do a timeline addressing her dealings with these other men AND with you, i.e. why were you her pick.
- Put a time limit on it...a week or maybe two...to get it done. You're not going to wait forever for it. Non-negotiable.
- Stress that the only way to move past this (you won't ever truly get over it) is with complete openness and honesty.
- Both of you read and discuss How to help your spouse heal from your affair, by Linda McDonald. Non-negotiable.
- As has been suggested, get a lie detector test for both of you to address your concerns and hers. Do this after you get the
timeline, but let her know you're going to use it to have the questions tailored to your situation and to test her honesty.
- Keep your head up and BE FIRM! No matter what society says, I feel women hate weakness and vulnerability in men and there's
no greater turn-off for them. JMHO.
Once you get the truth, (or as much of it you can stand), you might consider confronting your so-called friend and call him out. Let him know just what you think of him and he should lose your number. Let your wife know this will happen if you decide you need to do it. You might tell her that you may contact him for closure as a mean to get her to be more forthcoming. DO NOT LIE or BLUFF! You may do it or you may not. You haven't decided yet, but if you do decide to, it will happen.
Be careful with this though. My XWW's AP said some horrific things to me when I confronted. Really emasculating. Fortunately he was vulnerable because he was high-ranking reserve military and had a very high security clearance (above top secret) which he was parleying to get a lucrative job with a contractor, which he lost when I told his commander. So I was able to torpedo two of his carreers, his future and his marriage. He didn't think I had the stones to go there.
Last I heard, his wife divorced him and took him for everything she could, which was a lot! It still gives me the warm and fuzzies when it comes to mind.
Your guy might not have that situation, so again, be careful.
Lastly...give yourself time! It may take years to get through this and move on. Good luck!