she claims to not know the exact date that they first got physical but has said it was around thanksgiving...
This is a lie. She knows the exact date and time and where it was and what he wore and what she wore. This is the love of her life. She was ready to leave her long-time husband and her kids for this man. She knows every date and time, the first time he held her hand, the first time he kissed her, the first time she told him she loved him, and the first time he told her he loved her.
Based on other experiences here, very likely it started much earlier, maybe around October 1. She met him in July. He already was working there, she was "the new girl," he showed her the ropes, she was thankful for his help, meanwhile as soon as she started, he was all over her immediately - fresh meat. The compliments started fast, she enjoyed it. As your wife said, it was mutual attraction, and it went pretty fast.
Very possibly, this is how it happened: Early on, at some point, she rationalized stepping over boundaries. It felt good, he was saying inappropriate things to a married woman, she was doing nothing wrong (she knew it was wrong to accept the compliments and not tell him to "stop it, I'm married" but she rationalized her words and actions were not across the line). Then when this man kept telling her how hot she was, how sexy she was, how funny, and emphasizing how connected they were, she started to fall in love with him.
This was wrong, but it was feelings, and she really had no control over these feelings. But, like feeling good about eating a bowl of ice cream, she could have refrained and stepped away, went on a "diet" so to speak. But he kept handing over the ice cream and she kept eating it. And she by this time started to give feedback to him, she basically gave "me too's" to him, "I think you're hot, too" and "I think you're sexy, handsome, funny," etc. She found him confident, definitely he was bold, likely arrogant, and he made her laugh, and most of all, she felt desired and wanted and sexy and alive like she hasn't felt since she's been in high school, since she first met you.
So then she questioned her marriage and you, whereas she had been having sex with you, happy with your long union, the many successes financially and as a family, the prosperity of your house and bank accounts, the happy and well-adjusted kids, and she was a big part of that, and she respected you for it, but neither you nor her were in that passionate "butterflies" can't-keep-our-hands-off-each-other phase. And her sexual romantic interest, which had been on auto-pilot with you, transferred over to him. And decreased markedly to you. This last bit, you can figure out if that was true, you would have seen her stop initiating with you around the time she started having sex with him, somewhere between Oct. 1 and Thanksgiving. Sex with you would have been something she did out of not making waves, if she did it at all.
Plus, there would have been some times when you initiated the same day she had already done it with him, and she would have either made up an excuse why she couldn't with you or at least take a shower first.
What she would have done pretty early on is scope out his situation - who is his wife, girlfriend or last ex, their names, and basically "who is the competition." Then she would have compared herself against the competition, and see if she was "winning." She would reach a point she wanted to win him over.
She would have found out his birthday. The same way she acted with you when she fell in love with you, she probably would have done the same type of stuff with him. So if she was emotional and mushy and romantic and emphasized on things like "one-month anniversary" when she met you, then likely she would revert back to that way with him. Does your wife know the date of her first date with you? The first sex with you? If you could read all of their messages, you would see how teenage-ish and high-school-ish it was.
So on Jan. 17 she asks for a separation, around the holidays she had decided to do this, it was her New Year's resolution, to leave you and be with him, she had met him in July and was "in love" and having sex by Oct. 1 or so, and decided that she would let the kids have one last good holidays, Thanksgiving to the end of the year, and then she would separate. Hopefully you would move out and she and her would stay in the home and you could go live in a hovel somewhere, it doesn't really matter to her, just out.
Then she would go through the motions with you, never re-attach, and she would continue with other man, and if things went well, she'd have it set up to move from you to him permanently around March. She'd ask you for a divorce, and then after that she could tell everyone that this good "friend," a very, very good friend, who also had been divorced, he was a coworker who always was nice, very respectable, honorable, and he helped her get over her failed marriage, her husband who had drifted away from her, and she would tell everyone "aren't you so happy for me, that 'friendship' turned into so much more, like soulmates, and this only happened AFTER she had already left the marriage."
So of course Jan. 1 came and went and the other man hemmed and hawed and gave some excuses, and your wife pushed on it, and he liked the sex, and sure he liked your wife, why wouldn't he, but he wasn't ready to take on her baggage full time, he didn't want to have to rub her damn legs with the restless leg syndrome, that probably bothered him somewhat and got in the way of pre-sex or post-sex, all the annoying shit he had to put up with over her little habits and annoyances, like "could you rub my legs." He figured he liked it how it was, but he got pushed into a corner and had to tell her he wanted a future with her, but he really was hesitant on that.
Plus, you know your wife, she's a procrastinator just like you. So Jan. 17 comes and you have a fight with her, everything you did and say to her had become annoying as hell, and when you didn't follow protocol on the laundry basket, that was the time she could do it, she caught you doing something wrong, and she now had "good reason" to hit you with it, and she finally does it, asks for the separation. The laundry basket just showed her again how you just don't appreciate her, and her soulmate co-worker/friend/lover does appreciate her in every way.
Also, your wife is working on a nice easy job that pays just about zero towards finances, but you are not acting like she is making a huge contribution to the family, and really she is. Probably it is true that you did not fully appreciate her as a homemaker and mother, you figured she is doing her fair share and so are you, but now she is working, too, and you just didn't make a big enough of a deal over it. Probably this was discussed with other man, who told her how she is right, you take her for granted, and he NEVER would, especially a hot little piece of ass like her.
But you dig, and though you don't find the sex, you find enough, and that throws off her story about other man was just a friend, and then your reaction threw her off, she thought you wouldn't care so much, because the other man had been hot and heavy and all over her and you had just been on auto-pilot, routine. Plus your wife has a lot of issues, baggage. Plus she can sense other man really doesn't want this. So she pulls back on the separation.
Then rather than hit her hard with shock and awe, you kind of play the pick-me dance for a few weeks, begging her for any scrap. Meanwhile, other man is not doing the right thing by her, he is happy enough with the way things are, and she is giving some excuses, better to stay together until the end of the school year, blah, blah, blah. You're asking and she feels sorry for you, she's screwed up anyway now because of other man's games, and she feels like your her father or something, like you can't or won't leave her no matter what, and she needs some support, so she keeps seeing other man. On Feb. 4 you catch her on the VAR and she admits to the minimum, that she told him she loved him and was turned on by him and she was making out with him. By now you must know it was something more than that, "relations" you called it.
On Feb. 5 you post here and you say you don't even know if she wants the marriage or not which, in case you don't know this, that means she does not want the marriage. So she didn't want it at that time. She clued other man in, and he didn't give her what she wanted to hear, that "he wants her now and leave your husband for me."
So it's two weeks, and here you are. Personally, I think she must have contacted him by now. Told him how she still loves him, maybe he told her "me too." But still he didn't give her the go-ahead. Maybe she met up with him for a cup of coffee and a kiss. Or maybe more. But I think by now she has contacted him, at the minimum, and got some reinforcement on her "feelings" for him.
Regardless, you know better than me that you're living in a world of shit right now. It's in your face every day. The damage is being done.
The exposure. I was initially against it. Even more so with the kids. I think exposure is situational, only do it if it benefits you. Maybe it just makes you feel better. Maybe it gives you support. Maybe the ones who learn about the affair can influence your wife. Maybe it can "wake" her up to the fantasy feelings of the past 4-5 months. vs. the previous 16 years. My wife did everything I asked, and I never exposed other than other man's wife and his job, which I got him fired. But I didn't need the support, and I determined if eventually I decided to reconcile, my family and even hers were, too, fiercely loyal to me, and they always would treat her differently, and she would never live it down, and I didn't want that. Despite the affair, she had sacrificed for me many times over almost 20 years, and I am very loyal that way, too, so even if we divorced, I might always remember the affair, but I'd also always remember the many things she did for me over the years.
When I confronted my wife about the affair, within a couple minutes I had started encouraging her to go be with other man, I'd help her pack, I didn't want to prevent these two soulmates to be with each other - and I really didn't. I wasn't faking. It hurt like hell she cheated on me, but even worse to me would be if she stayed with me if she didn't love me and want me, that I couldn't bear, so if she wanted him, she should go, I'll be fair in a divorce. Now if you could imagine saying shit like that in the most angry way possible, that was me. Now if she was just shining me on and really stayed with me because he was not viable, then she lied and did a good enough job to convince me.
So really I don't understand wanting to stay where you are not wanted, where she is "torn" between a husband of an extremely successful union of 16 years vs. a piece of shit she met 7 months ago. As much as practically every new betrayed spouse seems to have this mindset, it is anathema to me.
But back to exposure. IF you want it, you should be much more forceful about it, I think. Not let her be in the driving seat. Though I watch so many guys fail here on regular basis, you can either fail today or fail next week, the way you handle it, the way most handle it the same way, almost guarantees it, in my opinion. And I think that is backed up if you read the threads here, littered with meekness and fear of losing, almost a self-fulfilled prophecy, and the cheaters, risk-takers, bold, and definitely not afraid of losing their betrayed spouses, hurting their betrayed spouses, despite their hollow words. But as bold as they are, they are morally bankrupt, at least temporarily. But some precious few do "make it" waiting and hoping, though I think despite of it and not because of it.
So exposure, I personally wouldn't want to do it with my kids, though if push came to shove and I got divorced and the cheating was the reason and they were at least teenagers, I would tell them the truth in a sanitized way. My family and hers I would tell them she fell in love with another man and still has deep feelings, she is "torn" between me, her husband of 16 years, and some piece of shit she met at work in July, she lied to me about sex, she lied to me about not contacting him, and I can't even tell if she's lying or not now, so I'm leaving her. I guess you would leave out the "leaving" part.
What others have done, which might be what you want, is to tell her family and yours that she cheated and is torn, and you ask them to support you and her to re-commit to the marriage and influence her to re-commit to the marriage and away from the other man, who you should refer by his full name.