SurvivingInfidelity.com^®

she really behaved with him as a friend.

I'm sorry my friend, but...

They only had these moments that started and ended with intercourse.

Those moments negate any type of "just friends" claim. This was a full blown affair. Just because they didn't have intercourse every time they met doesn't mean there wasn't an emotional component to it. There is such a thing as an emotional affair, and it can be just as devastating as a full blown physical affair. I think perhaps this is something you might need to come to terms with.

The fact is I have accepted this was an affair. Just I’m full sold she thought honestly she could keep this as a friendship and she actually struggled at first at understanding herself and the situation she was. While talking to her I highlighted some behaviour he had that clearly were ment to keep the affair open and that she mistook for friendship naivities (such as sleeping in the same bes as "friends").

Being tough here, seems like you are just making excuses for her bad behavior. There is no excuse for cheating. It a betrayal of the highest order.

There are other ways to deal with anxiety, whatever she had.

I do believe some people can be friends with opposite sex, and keep it as friends only. Some can't. She cheated, betrayed you.

You say you except it was an affair, good, it was, she chose to cheat, it wasn't an accident. Could be if you don't hold her accountable she may continue, if not with him with someone else.

You're writing a lot about your W and trying to understand her. That is a dead end. You need to start by focusing on yourself and on your thoughts and feelings.

What's going on with you? Happy? sad? Angry? Scared? Ashamed? Wanting? Not wanting? Where are you in this?

"I’m pretty sure that hetero spouses should not have opposite-sex friends. Acquaintances, ok. But not friends.

And if one has cheated, for sure, no more opposite-sex friends for them.

I know it’s not a popular opinion."

This. I think you were invited to the museums, etc. only because it would have been suspicious had you not and they knew you would probably decline so win-win for them

Your wife was enjoying the best of both worlds. She had you at home for Safety and Security and she had him for fun and excitement and validation

Her being sad that he ended all communication is a big slap in your face IMO. She should be terrified that you will divorce her but she's not because she knows/assumes you are not even considering it which gives her the power/control of the relationship

I’m not bit on offering people leeways...
Like I think your wife is truly 100% accountable for her affair, even if she was seeking false validation, has low self-esteem or whatever. Those factors might help understand WHY she did it, and therefore be a factor in helping prevent a repeat. But explaining does not justify.

However...
The OM...
As a rule I say the OP doesn’t really matter.
I’m making an exception in your case.
He had an affair with your wife. He visited your house, accepted you hospitality. Probably had some friendly conversations with you. He slept with your wife.

To me that would be so much disrespect that I would never want anything ever to do with such a person. It’s such a display of power, aggression, ownership...

I think you should make your wife aware of how extreme his behavior is, and how disrespectful she was in inviting this into your home.
Don’t dwell on it – it’s happened, over and hopefully your wife is on the path of reconciliation.
But make it very clear to her how extreme that is. Even beyond "simply" going elsewhere to do the lateral river-dance with him.

I would make it known to him that you despise him and think him the scum of the Earth and you don’t want anything to do with him or his presence ever again. I also think that the other "friends" that went to his place should be out of your life.