After my divorce I cheated a lot, on a number of boyfriends. I'll be honest, it was for no reason other than I was a horribly selfish person, and out to prove to myself that just because my husband didn't want me, well, there were lots of guys who did. I didn't get caught, but I honestly wouldn't have cared if I did. I was in a place where my emotional and sexual validation was so important and blinding (for all the wrong reasons) that it made my boyfriend's feelings irrelevant. Yeah, I was a shitty person. I would never cheat now. I've finally reached a point where I'm ok with admitting that the social norm of monogamy doesn't work for me. I do not equate sex with love or other mushy feelings, and I'm in an open relationship which is fabulous and fulfilling for me. That being said, I can count on one hand how many times I've actually taken advantage of the open relationship free pass in the last 9 months. There are still ways you can cheat and break the rules, and I'd never even contemplate it now. I'm not sure what's changed to make that true now though. Perhaps it's that I am completely fulfilled both sexually and emotionally. Maybe it's the fact that the fruit is no longer forbidden, or maybe it's that I just grew the fuck up and stopped being a selfish asshole. Honestly, I think it's a combination of those things and because I truly, 110% believe that there is no man on the planet that can give it to me like mine does, so why bother? The few times I have slept with other people, it was disappointing in the extreme. I do know that if I were to try monogamy again, it probably wouldn't last long. Oh, and by the way, The Ethical Slut really is a good read, don't knock it.
The most valuable thing I have is my word. Cheating's wrong. If a monogamous relationship isn't working for you, then don't lead others to believe it is. I am inclined to give more tolerance to cheaters who are in a situation where breaking up isn't as clean a split (custody issues, survivability), but it is still best avoided. Nothing wrong with an open relationship, go for that if that'll make everyone happy.