First of all, I am very sorry about your wife, I really know what it feels like to lose someone to cancer since I also lost my father to cancer, when I was 11 years old. I wish you strength and health.

I think having as intimate and strong a bond as you can with just one other person who returns that in full is one of the most valuable things a person can have in life.

Now to this, I'm not saying that psychological bonds or intimacy are not important or bad. What I really mean is that people demonize another equally important and good form of intimacy, physical and sexual, and for younger people, experimentation without commitments before a more serious relationship, which even correlates with a greater likelihood of being satisfied in future serious relationships (monogamous or polygamous), and less likelihood of cheating. Although polygamous AND open relationships, I think they are the best, even if on the other hand they are more difficult to have and maintain, because there is evidence that points to the fact that people are less likely to feel dissatisfied with a relationship if they can still experiment with other people.

It feels so wrong to both her and anyone I would move on to and such a betrayal of my own personal values that it's unthinkable to me on the level of cannibalism. When people expect me to move on my revulsion is what I expect it would be if there was a dead person laying there and those people expected me to start eating them.

This is clearly a false equivalency fallacy. You can't compare those things. I don't think that getting another couple is something bad or makes everything you promised to her false. You may not like to do that, and that's totally respectable, but criminalizing or dehumanizing it is way too much. I think that's part of letting go, and I'm not trying to minimize your feelings nor the feelings of people that's living something similar, but telling that it's a form of self-care and self-healing.