I (M35) found out my wife (F38) slept with someone 2 years ago. Been together 10 years. Don't know what to do...

Damned, this got long... but writing all down got me somehow feel better. This is btw a throwaway as she might read my stuff. I'll try to be as objective as I can.

So, where should I start... maybe the situation last week: happy together, two kids both under 8yo.

And now we go back to 3 years ago. Her affection towards me was getting smaller by the day. I was getting exhausted being the one doing all the work at home, next to my daily job. 2 kids, I was mainly taking care of them. And then I started nagging about it, was desperate for some attention, tried to make some romantic efforts, nothing helped.

I started noticing she was on her phone a lot (this is summer '14). Until sometimes 4am. Somehow we started having more sex, but without feelings. I suspected her of chatting with someone else, she denied. I got out of my mind, took her phone when she didn't notice (I know, this is wrong, but was getting crazy of desperation) and my suspicions got confirmed. I confronted her, she got mad for checking her personal messaging. She said the sexting was nothing to be worried about. All just "virtual", as she said.

I got depressed (because I didn't get any of those words she had been writing to someone else). Couldn't get her attention anymore. So I checked her tablet a month later, to know if it was still going on. The tablet showed photos she had been taking on her phone. Photos of her, showing of her body's best parts (clothed), obviously they were sent to the other guy (let's call him Guy). Guy lived btw in abroad. She found out again I was spying on her, and found that so offensive she filed for divorce. So we decided we were only living together until she finds a job abroad, and we would both move over there as we have kids (I didn't agree on that). Surprisingly she was eager to move to the country Guy was living. She made it clear we would never be together anymore.

I was seeing a psychiatrist, and was getting back on my feet. She continued with what she was doing. Once caught her by accident taking pictures of herself in lingerie, she even was getting waxed downstairs. She visited the country where Guy was living. Told me she didn't meet him, she was there only looking for jobs.

One day (valentines 2015) I was going out with friends, and by accident met this beautiful Girl, just at the point where I thought this would never happen. We started seeing each other, and had mutual strong feelings. Wife noticed, because I was open about it, not rubbing it in her face, I just answered her question who I was going out with.

Wife changed completely, send me messages if she had lost me. Even informed her father about me seeing Girl, he called me and asked me to stop the new relationship. Wife started to show super interest in me, also sexually. I bent under pressure (thought about the kids a lot), and said goodbye to Girl. Wife was pleased. I had double feelings. Wife promised me she hadn't seen Guy IRL, also hadn't sent any nudes to anyone (which I doubted) but I believed her (I am stupid).

But it didn't get any better, I had a feeling she was texting Guy again, but I didn't care anymore. Psychiatrist learned me some tricks to let it go and I concentrated on my kids and my job. We weren't divorced yet for real, the paper was in, but needed the final confirmation. Somehow wife was again pro divorce. I had a feeling this wasn't fair, but didn't care too much.

Fast forward to Christmas 2015: wife had suddenly her necklace on again which I made her for our wedding. Since then I didn't feel her giving attention to others anymore the same way she had been doing, we were back on the right track, I was happy because I still cared a lot about her. I had been thinking she might had been depressed by her work and needed this other kind of virtual relation, and was happy I was right.

Now back to 2017. A month ago wife was going out with a friend back from high school. She sees him every now and then, when he is in town traveling for work. Well this time she came home, drunk, in the early morning. When she woke up she admitted she had spent time with him in his hotel room (I confronted her, knowing no bars were open anymore). She promised me nothing had happened, they had only listened to music and stuff... I said I believed her, as she was feeling sorry for doing so.

Some weeks ago I was on her computer for totally other reasons, but still thinking about that hotel night, I thought I would look if she had any messages from high school dude. She didn't. Instead I found a shitload of pictures she had been sending and receiving. Nudes, last one was November 2015. Also messages, these were the most interesting. I found out that:

1. Guy started seeing someone more interesting, Wife then sent pictures to him of her crying December 2015. So wife loosing him was basically the reason she decided to go back with me.
2. A message string revealed a new man, someone she had met during a business trip (April 2015). He told her how great their night had been, showering together etc. They chatted for about 2 months.

So, now I know for sure she has been sleeping with someone else. I can not confront her with what I know, as the way I found out was kind of illegal. If I say I was going through her personal stuff, she will feel I did more wrong than herself. I think she has somehow a narcissistic personality. What should I do?

I myself feel now very strongly that this should be the end of the relationship

Again, sorry for this being so long and boring with no funny puns at all. I usually am not this serious.

Tldr; mid 2014 - end 2015 wife has been chatting with another guy. Since then back together, she promised me she hasn't had physical contact with other men during this time. Recently found out she lied.