Re: My wife mad at me after 3sum with another man.
While I agree that alcohol does not excuse her actions, as she shouldn't drink if she can't control herself, I do also think you do bear some responsibility here.
I get that you guys had had some previous discussions regarding the possibility of having a threesome. The thing is, though, there had been no firm decision to go forward with it. And I'm inclined to think that part of that is because she maybe wasn't sure she really wanted to do that. She might have felt some guilt and discomfort at the thought of doing it, she might have been worried about how you would feel if you two did it. She might have been afraid you would later think poorly of her or blame her, or even that you might want her to do it all the time, when she only wanted to do it as a one time thing.
Perhaps I look at it differently; I would never have a threesome, nor would he. We are too jealous to bear even the thought of each other sleeping with someone else. So, to me, it would indicate a serious problem in our relationship if he not only didn't get upset and stop me when flirting with another man, but instead joined in. At the same time, I would also think it indicated a serious problem if I was not only flirting, but attempting to go farther than flirting, with another man.
I think the best bet for getting past this now is to tell her you were wrong for handling it the way you did and to agree, together, that in the future, if you two (or either of you) is drinking, that things like this will not occur. Agree that any further discussions of threesomes will only take place while completely sober, and that the actual act itself, if it occurs again, will only take place sober, or that drinking will not occur until AFTER the decision has officially been made.