I ignored her needs and she forgot how it felt like to be adored and cherished.
I agree she really enjoyed feeling adored and cherished by the other man. I think that are true feelings. Problem is, it is bullshit to tell you that you "ignored her needs." You did everything she asked. She was acting happy with you, not too long ago, when the last child left for college, she told you she wanted to have sex with you all over the house, in every room and place. She asked for botox, implants, etc.
You are not a mind-reader. If she didn't tell you, "Husband, you are not making me feel adored and cherished, these are important needs you are not meeting," then she can't validly blame you for not doing anything when everything seemed happy. Even if she had told you and you ignored anyway, cheating wasn't going to fix the problem.
But this is not how cheating happens usually, the cheater doesn't even know they are missing something, then an affair partner shows some interest, and the cheater, instead of telling loyal spouse, instead just pushes forward with the affair partner, and rationalize that the loyal spouse won't be hurt by what they don't know. I don't even think usually they blame you for the cheating while the cheating occurs, only afterward.
Regardless, it is a tough situation because it is so explosive, you on the hurt of betrayal, her on the guilt and shame and being the one who caused it, but not wanting to be.
As far as what they did sexually, I previously referred it to as a sexual circus. She moved in for him for a week, and they both knew this was a TEMPORARY situation - so I would assume that he, and she, would have gone to all the things they never did before and really wanted to. No kink would be beyond. I'm sorry, and I could be wrong, but that would be my assumption based on her specific circumstance of how she left openly.
I also don't think the sex was any big deal to her, I think it was much more emotional than sexual, though she had no limits and no qualms about the sex. I think she had good sex with you, but this guy was new, and she had feelings for him, the infatuation. I also think the sex likely began well before that week.
I think you're doing OK still. Move forward with the divorce, she can either come around or not. I would suggest trying to stop arguing with her, stop talking about the requirements, if she ever asks you about not divorcing, staying together, just tell her that you've already told her what you would need, if she doesn't want it, if you are not important enough for her to do it, she should move on. Because you are important enough.