There have been several epic, massively digressive threads about this subject. I will say that virtually every BH who perceives that his WW was more sexual with her AP desires her to be as sexual with him, or moreso, after DDay. That feeling by the BH is 100% normal and legitimate. As a feeling.
It is also 100% true that a wife doesn't "owe" sex to a husband. Period.
More to the point of your question, you can't make a woman feel desire she doesn't feel, nor can you manipulate her into feeling it by being obsequious, or offering things like acts of service glazed with faux flattery tinged with the bitterness and anger you are so clearly bottling up inside. You might guilt her into faking desire or grudgingly acceding to sex acts she doesn't wish to engage in with you, but would you really want that?
I would note also that where a WW is caught in an affair and truly wants to reconcile with her husband, it is very common that the WW sex-bombs the BH. The fact that your WW has not done that tells you pretty much all you need to know about where her heart resides in terms of desire for true reconciliation with you. She presumably knows that you have chosen to preclude divorce as an option (at least divorce initiated by you -- keep in mind that she could choose to divorce you at any time). At age 65, you both have entered the fourth quarter. She has been or will be going through normal physical changes that diminish her sexual appetite. She's had her life's epic love affair and has built the memories of it that she can cherish in her waning years. You are a comfy runway to coast out her final years without a lot of disruption. She says she "loves" you. There are multiple kinds of love. In your case, it's philia, not eros. You need to be clear on that.
The underlying facts of your thread are unusual because she functionally divorced you in secret, keeping you around as a roommate and source of income, while marrying another man. The desire she harbored for him, the cocoon of intimacy she wove with him, those are places she still clearly harbors and cherishes. It's equally clear that you will never have those things with her. You are clearly Plan B in terms of eros.
You have stated in other comments that you will not consider divorce. That is of course your prerogative. However, the standard advice to any betrayed person is (a) figure out what you want and need to be satisfied with your marriage, and (b) if you're not getting those things, leave the marriage. In business, you negotiate from a position of strength if you have options and your adverse party is aware you have options. Because of your choice to take divorce off the table no matter what, you have zero options. This is why you are here functionally asking the same question over and over: "Why won't my wife do what I wish she would do to make me feel better?"
The answer to your question is simple and obvious: She won't do what you wish she would do because she doesn't want to. She has no desire to. Your WW was highly sexual with the AP because she desired him in that way. She is not highly sexual with you because she does not desire you in that way. She has no imperative to help you heal. She's fine cohabiting with you and your bitterness to the grave.
People here will try to ameliorate your pain by talking about the "fantasy" element in the affair, how it wasn't real, how it's functionally a transactional exchange of ego kibbles for pussy, all that. Explaining a thing is not the same as excusing a thing. From the perspective of your sexual satisfaction, does the "why" matter? Whatever psychobabble people use to describe the etiology of her desire, in the end, she desired the AP, but she doesn't desire you.
Furthermore, in most affairs that "pussy for kibbles" calculus lasts around 4-9 months, maybe a year. Where it went on for 15 solid years, it's clear that it was something else. Your wife had a love affair. A marriage, really. Her heart and mind resolved a decade or more ago in terms of where her true love and passion resides. I'd remind you that her AP knew her truth. You're still getting TT. In terms of emotional intimacy, your WW shared a ton more intimacy with that AP than she has or will with you. In every respect except the paper on file downtown, the AP was her husband.
Which leads me to my suggestion. You have unwittingly been living a secret, one-sided open marriage since around age 50. Now that the affair is out in the open, you're still functionally living a one-sided open marriage because your WW's sexual desire and heart's longing still belong to her AP. Why not at least be honest about it and open the marriage all the way? Tell your wife that you will remain legally married to her, residing with her, etc., but that you're going to get yourself on the apps and find the sexual desire you crave. It would not be cheating because, unlike your WW, you would not be sneaking, hiding, and lying.
For men your age, as long as you are solvent, reasonably fit, and your junk still points north when called upon to do so, the world is a cornucopia of sexual opportunity. Widows. Divorcees. Long-neglected married women. I'm around your age. I have several buddies our age who have divorced in the last five or so years. Their experience has been uniform on this point. The most recent met a widow who had been the primary caretaker for her husband as he slowly died from cancer. She said: "Honey, I haven't had sex in 15 years and I intend to make up for lost time." Find yourself a woman like that. Tell your wife that, because the passion you have been deprived of is clearly not going to be available at home, you intend to spend the next ten years or so going out into the world to find it. But unlike her, you're not going to lie about it, nor sneak around. She can choose to take it or leave it.
Right now, what she has on offer for you for the rest of your years is the scraps of her life. The leftovers now that her true love has moved out of her life. You don't have to settle for scraps.
[This message edited by Butforthegrace at 2:07 PM, Friday, June 6th]