TnGuy....you have found a website with a specific section that focuses upon saving marriages after an affair. Therefore, at this particular site, you are only reading about people who are struggling trying to mend their relationships after infidelity.
However, if you wanted to, you could probably do a search and find a website full of people whose common theme is "I kicked his/her cheating a** out the door the moment I found out...lets all rally together and talk about what a**holes our cheating spouses are!"
So what I am getting at is that there are plenty of people who feel the same way you do and who would never forgive infidelity.
It was interesting to read that you had been cheated on and dumped her butt the moment she told you about it. So you do have some experience with this. However, a 2.5 year girlfriend is not the same as the mother of your children who you've been married to for 10-20 years, as is the case with many on this forum. There truly is no comparison to what you've experienced and what many here have experienced.
I myself cheated during my marriage. I admitted it to my husband, expecting him to leave me. He didn't leave me, we tried to work through it. 12 years later, we still hadn't worked through the issues which caused the infidelity to begin with and we finally divorced after 17 years total.
You could say that me cheating was a choice I made and had nothing to do with our marital issues. And you have every right to view it that way if you choose. But my husband and I knew better, and unfortunately, we never got the outside professional help we needed to be able to really "fix" things.
Now I am in a new relationship and am madly in love. I have no intention or desire to even look in another direction. My heart, body, and mind belong entirely to him...which does not mean we don't have our issues, we really do. But I do finally now have the emotional maturity necessary to be 100% faithful, regardless of other relationship issues. I finally learned all those lessons and moved past them.
However in my current relationship, if he cheated on me it would be over. I know that seems totally crazy coming from someone who has cheated, and I also know I may feel differently if it actually happened (as many people here are saying...they said it would be over too, until it happened to them). But the way I feel right now, given all that I have been through and learned is this: I could forgive him for the act. I could understand how it happens. I could be his friend again eventually. But I could never touch him again. And being that touch and sex are very important in our relationship, it would be over without touching and sex.
Some people have an easier time with this than others (not that it is easy for ANYONE...it is not). But some people can really put things in perspective when it comes to the touching part. Others can't.
As I said in the beginning, you can go find thousands of people who agree with you 100%. This forum is not going to be that place.
I actually do agree with you partially...in that I could not stay with him. But I disagree with you about the fact that it would automatically mean he is a despicable creature who deserves no forgiveness.
In my heart I know that we are all forgiveable, loveable, and good inside. Things happen which cause us to act in ways that are sometimes not loveable, not good, and not forgivable.
But being that none of us may judge the other, I think it would help you to drop your sword against your cousin's wife.
There is logic in what you are saying...that loyalty to your cousin is what is driving your feelings. However, from the outside, it sounds more like hate and spite for your ex-girlfriend that cheated on you, than loyalty to your cousin, that is driving your feelings.