It looks like we more or less agree, and the point of disagreement is the components of love, of which I think there are two: attraction and companionship. It is possible for a 50 year old husband to feel tempted to sleep with an attractive 25 year old who is trying to seduce him, while feeling deep love towards his 50 year old wife, who is now a lot less attractive than when he married her. He can feel tempted to cheat but at the same time feel bad about betraying his wife. Should they divorce? I'd argue in many cases, no.
I'd not, but my self-interest is rational, I'd never risk loosing the companionship of my wife who's intelligence I admire, who I find a great mother and a great enrichment of my life. I guess we do agree. As I said, perhaps I tend to harp to much on the ethics of rational self-interest. I tended to ignore my own needs in relationships, the works of Ayn Rand were a big eye opener.
For me that falls under taking responsibility for my own life. If I were to be constantly tempted it would be a signal something is wrong. I'd discuss this with my partner. Perhaps we should break up. The alternative is staying with him/her out of pity. Pity is not love, staying with someone out of pity is worse than leaving them imo. If my partner was constantly tempted but staying with me out of pity it would be the ultimate insult. I want my partner to be with me out of pure self-interest, because I'm the best choice, her favorite human being, her ultimate partner, the best she can get. I don't want to be a compromise.
I think that there is even a case to be made that leaving while you have children is better for them than keeping them in an unhappy marriage. You are certainly not giving a good show of what love is all about.
I do agree about the feeding, you certainly have the power to feed and deprive certain feelings.