I feel like I'm about to step in it, but here it goes:

The real question is: is cheating moral?

It's not cheating if your husband knows you're doing it. Some couples are polyamorous. So it's not about chastity.

So, I'm guessing he doesn't, otherwise you wouldn't be calling it cheating. Will it hurt him if he finds out? Are you keeping your cheating a secret, not to keep him from harm, but to continue to reap the benefits of being married to him? If so, aren't you hurting him? Are you keeping him from moving on and finding love so that you can continue to benefit from marraige? Do you care? Why is it ok to hurt your husband, but not ok to hurt other cheaters? Maybe you’re staying in the marriage for his benefit. You feel like leaving him would do more harm. I don’t know the situation. I don’t believe the sexual nature of something amplifies it. You might betray your husband in a non-sexual way and it would be just as wrong.

We all do things that hurt other people. Sometimes it's intentional, sometimes it isn't. When we recognize that what we are doing is hurting someone else and we refuse to try to stop because it benefits us in some way, that seems like predatorial to me. If it bothers you and you can't stop, that's weakness. That I understand. I have to work hard at not doing stuff that hurts my wife and I fail sometimes. In other words, I’m weak at times. I recognize it, I apologize for it and I make intentional plans to do better. However, if it doesn't bother you, that's malice. Moral/immoral whatever...intentional unrepentant malice makes you a bad person. After all, you are what you do. But it's a choice. You can stop being a bad person if you really want to.