I can certainly understand your sentiment. Cheating is cowardice for sure. Either communicate and fight like hell to save and fix your relationship or find a way to amicably and maturely go your separate ways.

That said I will politely disagree with you about the cheater never understanding any of the damage or pain, at least when it comes to a statement that includes all cheaters. I've also always had a problem with the notion, "once a cheater always a cheater." I know this because many years ago I cheated on my girlfriend. If I were to leave the story there, you'd hate me based on your OP. Heck, you may still hate me after I give you the backstory and you know what? That's ok. I also don't understand this idea that cheating can't be a mistake. Mistakes start with choice, those that weren't choices are accidents.

I was young (18 or 19) and my girlfriend of 1.5 years broke up with me. It was a long distance relationship and she told me that she kissed a guy at a party and that was enough for her to realize her heart wasn't in it anymore. Still away at college, I fought like hell to get back together with her and when I came home for the summer we hung out a few times and she was cold and distant. Still I kept fighting for the relationship all summer. Then it came time to go back to school and funny thing, I didn't care anymore. She sensed this and lo and behold wanted to get back together. I agreed because I thought it was what I wanted.

After a couple of weeks into the new school year, my friend introduced me to his sister. We instantly hit it off. Both in relationships, we got sucked into each other's worlds. We ended up kissing. For the two or three weeks before I broke up with my girlfriend, my attitude changed. I found myself upset and pained with actions. I found myself not trusting her or myself. I never considered myself to be one that would cheat. It was a miserable experience on several levels that I won't go into detail here.

The important point is that I learned that the person cheated on isn't the only one that is negatively affected by cheating. I say this having been on both sides in the same relationship. It was a valuable lesson and one that I've never forgotten. I can tell you that I promised myself that I would never cheat again...and I haven't after 10 years of marriage.

I guess my point is, it's ok to be hurt and pissed off...and every other emotion you may be feeling. I would only caution you to try not to get so caught up in your emotions that you lose yourself to them and blind yourself to other perspectives.