Scott, I saw your post just come up today, I haven't been here for a while, but I see you've made a lot of progress in a month, and I think you're doing a great job. I don't know how much I can add but I did want to put in a few comments. As a woman, perhaps.
Do not EVER EVER EVER EVER under any circumstances accept an open relationship with anyone. If it's what you wanted with an agreeable partner....I still think it would be a mistake, but it would be yours to make. But don't ever take this offer from anyone else, it almost never works out and it's a disaster prolonging and worsening an even worse disaster. I'm very glad you said no to that bullshit. That's keep you on the line while she sees if the other relationship is going to work out. The partner who is offered the OR is always the weak partner in the relationship - always. And the cheater wants you to be Plan B in case Plan A...the AP....doesn't work out.
Well, from what you're saying, it sounds like AP did not work out....or not as she thought it would, and you're not the chump she figured you were. After all these years, she thought she knew you so she could hide this from you, and when caught, she thought she could play you, and that's not true. Good for you! So that's why, IMO, she's trying to take up with you again, the bloom is off the AP rose, she's starting to think about what she might lose and you're not married, so depending on your state, she might have an inherently weaker position than a wife. In fact, that could be a reason for the affair, she might have wanted a different status or type of relationship. It sounds like she wanted change generally, and handled it very badly, as they usually do. An affair IS change, but it's not managed or constructive change and it's one sided. It's all about me, myself, and I.
I am NOT an advocate for Recon....almost never. Because the truth is, healing if you do it and it's way overrated, takes forever, and even decades down the road people still have feelings about this. It permanently changes how you view someone. It's not only the act itself and whatever went with it....it's how you VIEW them. It's like finding out your spouse was stealing money from old ladies, or had been a stripper in a bar somewhere or was selling crack to teenagers - I'm exaggerating, but if you found out anything like that....you can't view that person the same way again. You know MORE now and it does make a difference. You know what she's capable of and what she might do again in the future should similar feelings or needs arise. You know what sneak and liar she can be. And how manipulative with you. You know she'd consider an open relationship....at least for herself, but I bet she wouldn't be enthused if YOU went out on "dates". It's usually one way and it's their last chance effort to hold onto AP and the sucker they're married to.
It sounds like you're handling this well and go with your attorney's advice. The only thing I would advise if you do it, is to get away for a while - even just a weekend every so often until you end this process because it will help clear your mind and get you away from the stress. Being away from her WILL be good for you. It will give you perspective and maybe some fun. You need to have that in your life still. Even without this woman, you can have a good and happy life with a future. That's what widows and widowers face too.
My concern for you at this point and perhaps others have raised it here is if she is your only employee, how much can you trust her in various ways in your business at this point when it is likely you will be dissolving this relationship - and probably the business relationship too - you should do BOTH, IMO. I have a friend who went through something similar with his wife - pretty similar actually and she ended up stealing a lot of money from him...well, taking it out of their account whether that is stealing or not....it was underhanded to be sure. She went and moved out on her own eventually and the AP threw her out so....I don't know what she's doing now. He's not taking her back, but they're not rushing into divorce for various reasons, perhaps the business. If you haven't already had these business-employee talks with your lawyer, you might consider it. I personally think she should be eased out of the business but let them be your guide as I recognize it might be a more complex matter because of your personal relationship.
Again, as painful as this is, I think you are doing incredibly well, and I think you'll make it out successfully and have a good future. You can't live with someone who treats you like this. You're not Plan B. I'd just try to make some time for yourself away from her and that whole situation so you can refresh yourself and not be in a stressful situation so much.