I didn't say it was better or worse than beating your wife. I just stated I have no personal respect for a man who nailed his sister in law. Cheating is bad enough, but your sister in law? Give me a break dude.
If I judged everyone based on cheating and had it out for them, I would have no friends or few to speak of. You would be surprised by how many of your friends, even family members, have committed the act at one point in their life. We're human after all. We're imperfect, capable of committing error. Everyone is. As for myself, I have not cheated before, and do not believe in the idea or act of cheating. Having said that, people make mistakes.... it shouldn't be enough reason to dislike someone. Again, she was no slice of humble pie herself. Nor was she the best wife or person on her end. This does not mean it makes it right. I am just saying, it takes two in a relationship for why things fall apart. Many people cheat, because they aren't feeling loved or treated right at home. Sometimes people do it in fear of losing their so-called significant other... My ex as an example, did it to me in fears she would lose me after I asked for a two week break (her thought process led her to believe I was going to break up with her anyway, so she lost control).... little did she not know, that would be the reason I would end it. I don't give second chances for that sort of thing. Once that trust has been broken, I can't continue on. There are those who are of the selfish variety. They only think about themselves and not the person they are hurting, which is most often the case when a person cheats. They are presented with an opportunity and sometimes it comes down to weakness. Not having the strength to walk away. I been tested multiple times. It's strange how often women present themselves to you when you're in a relationship. They know this and some will still venture there. I admit, I recall coming close, because I didn't like how I was treated (so at one time, I almost felt justified), but it the end, I couldn't. Even though I knew my time was ending with my then partner, I respectively declined.
In the end, I think it's great you value relationships and the act of commitment, but unfortunately not everyone does. Again, how long ago was this? I am over it. So should you. It's a mistake and one that has cost him dearly. You should see what he pays out in alimony. Not like he would do it again. I am not supporting it. Just saying, some things deserve to be let go. I been cheated on by more than one individual. Well, that isn't fair. Only once I can recall where the person confessed, but I know my last ex had a boyfriend weeks after breaking up with me, so I am imagining she was seeing the guy before we broke up. She denies it, but I have my doubts. Whether the case, the one who cheated on me, I ended up taking myself out of that relationship. I forgave her years later and have since moved on. I suggest you to do the same. It's not good to hold it against people like that.
If I can forgive a person who did it to me, I think we can forgive some person we don't know.