Update:
So I finally had this discussion with her last night. Something else came up completely unrelated that we got to talking about with some members of her side of the family and I figured this was a good a time as any and it would save me from having to bring the topic up completely on its own.
Overall, I think it went over pretty well. I told her simply that I don't think it's a good idea for her to continue seeing these 2 friends of hers that puts her in an environment that is (and I quote) 'conducive to a certain social fraternization between men and women'. I did get her to admit that she had been drinking that night she had come home. I did not actually know this, but it isn't surprising either. I used this information to give me a bit of an upper hand by saying that every time she goes out with them, you end up some place drinking. The last time she was out they ended up drinking somewhere. I told her I don't need her out on a weekend night drinking because it is disrespectful to me and to our marriage. I asked her if she thinks I'm just totally naive about what goes on whenever women are out at night drinking.
She tried to retort that women can't simply go out to have a drink and just talk? I honestly believe her in that I don't think she's truly getting her game on by flirting with men who may be at the same venue, but I do not believe that the 2 friends she's with wouldn't engage in that behavior. She said they're not out drinking and throwing themselves at men. I replied that's not really what I mean, I expect there's plenty of thirty guys who are drinking and throwing themselves at you or them. Even if it never actually happened, the environment you're in is conducive to it. Sort of like college girls going to a big frat party - they go there for drinking, sex, maybe occasionally some drugs. You really expect me to believe you're shocked that stuff like that would happen when you're out with them?
I continued that I'm not trying to tell her she can't see these 2 friends of her's anymore. They only get together maybe twice a year anyway. I stated that she could simply try to make plans with them to go out for lunch one day, or maybe make a trip to a spa instead. Well the big concern then was that the one friend whom she has known longer than we've been together will immediately start wondering what's going on with regard to why she can't go out at night like they've usually done. She said she'd have to frame it in a way so that they're not trying to blame me. I asked why this was a big concern, what was the big deal? She said that if the next time they try to get together and she says she can't really go out that night that immediately the one friend will probably ask "It's Saul isn't it? He's telling you you can't go out" (meaning I'm being possessive or controlling of her).
Ah yes...plenty of men have been down the road on this one before haven't we? All the regulars who are reading this now know exactly how this sh!t turns out, right? Before I continue with how I handled this situation, let give a quick backstory....
Background
My wife's dad passed away a number of years ago. When I first started dating her, we did the usual meet the parents eventually and for me, my personality is such that it just takes time for me to really get to know anyone in a more than casual manner which I knew would be the case for her parents since I considered this something serious for an LTR. Her dad one night decided to go off on me for no real reason. It was very disrespectful toward me and I don't tolerate that crap from anyone so we left immediately and I refused to speak to the man for years afterward. He eventually passed away without us ever reconciling or anything at all.
I found out after that event that that was his sort of way of trying to vet me I guess. Wanted to see if I'd supplicate myself to him like I guess he's done with other guys that his daughters had been seeing. I am guessing I was the only one to essentially tell him to f*ck off? The point I'm trying to make with all of this background is that my wife has told me that when she was a girl and teenager that she hated how controlling her dad could be at times and when they occasionally butted heads, it only made her more steadfast in her resolve.
Right now, i don't hate the guy anymore even though we never reconciled, but I can appreciate the fact that sometimes he may have needed to be this controlling a$$hole she's mentioned and I have once told her about this during an argument that we had. I stated to her that maybe her dad had been this way since she was (at the time of the argument) still acting like spoiled teenage girl with a bratty attitude. I further told her that she needed to act like a grown up woman and not this teenager cause I'm not interested in cleaning up any woman's mess, I need a woman who handles that mess herself and acts like a proper wife and mother to our kids. That seemed to take her back for a while and I'm guessing she never thought about it like that.
During all those years of her growing up, this one friend I mentioned was there with her through all of it. I suspect she's keenly tuned in to the controlling dad factor she's known about her for years.
So back to the main story...
I told her that I can appreciate the longevity of her friendship and how she treasures it considering they've known each other for like 20 years. I respect that because the two of you have worked to try and keep the friendship going. But I also slammed it home that her friend does not have carte blanche say in anything in her life nor mine and she damn sure has zero input on our marriage. I told her it isn't a one way street in that I alone have to respect her enduring friendship; her friend MUST respect our marriage and give consideration to how MY WIFE is out in public and its perception with other people and myself. If my wife is out with single friends drinking on a Saturday night, what is the perception by other men? How do I as a man and husband perceive it? Neither of those questions have good answers and the fact that the get-togethers they've been having result in going out at night drinking tells me that her friend still doesn't entirely respect me or our marriage.
I flatly told her that if she communicates this properly to her friend what I just said and it doesn't go over well, I'd be more than happy to speak with her myself but I also told my wife that if such a situation occurs, I am not going to lose. Yes, I literally said the underlined words. I'd be more than happy to be the bad guy if that's what it takes and to drive the final nail in the coffin of this whole discussion, I asked her that if I hadn't brought this up at all, do you think that, say, in another 5 years you and her would still be doing the same thing? She acknowledged that it most likely would continue, yes. I told her than in 5 more years our oldest daughter would be a teenager and teenagers get curious about sex and drinking typically goes along with it. I do NOT need a wife who engages in activities which could be perceived as condoning that sort of stuff in a marriage if I want any decent chance of our daughter turning out to not be some party animal or worse.
So the result ended up being that she really didn't have any good arguments at all to any of the stuff I said. She, like every woman, gets the occasional emotional flare-up with tears, maybe a bit of crying, in an effort to soften the perceived attack but being with a woman for so long it stopped working many years ago. It's one of those instinctive responses that women can't seem to shake, but how men react to it is entirely up to the man. Most men simply don't think and want to console the woman immediately. F*ck that. I gave my word for this marriage and I'm going to make sure it f*cking works properly. Guarding my wife is not controlling and I won't feel bad no matter what insult someone hurls at me.