Wow - very well said. If a man know it hurts his wife, and he does it anyway, he is very much "cheating" (and I would say abusing). You have given me much to think about.
You know, this kind of stuff is really tough, even for adults to discuss.
If it makes any difference, I think it comes down to this for me spiritually...
Selfishness is sin. We are a sinful by nature. Therefore, to do good, and to resist our nature, we look humbly to God for help.
And there you have my "in a nutshell" spiritual perspective on the entire conflict between good and evil in this world.