Lyssa, I take it that what you're saying here is that your husband is spending excessive (in your mind, at least) time masturbating to computer porn, correct? At the same time, you describe your sex life as good. I would be somewhat concerned if he'd lost his interest in you, but that does not seem to be the case. It's possible that he simply enjoys masturbating. With sex for one, you don't have the concern with pleasing your partner and can concentrate on yourself. That can be very fulfilling, and as long as it isn't a substitute for sex together, I don't see a problem with that aspect of it.
Looking at porn is enjoyable and usually harmless, but it is possible for people to be addicted to it. Generally though, from what I've read, true porn addicts withdraw from other forms of sexual activity and
need porn for gratification. I'm not sure, in your case, if that's what's going on.
If your sex life is good, I think it’s highly likely he finds you attractive. I doubt that he’s trying to replace you with these pictures. Most guys, even this 44-year-old one, just like looking at naked women, whether it’s pictures or the real thing
But, if his looking at porn is bothering you, I think you should speak up about it. Have you ever talked to him about it and told him how you feel? It's also possible that you'd both benefit from some professional counseling. It can really open lines of communication. Good luck in finding resolution. Please know that you’re very welcome here and that we care about helping you out.
-B