What men do is masturbating. Sex can't replace masturbation, at least not completely. It's a fact that porn makes masturbation more pleasurefull so if he uses porn to masturbate it's completely normal. This doesn't mean he doesn't love you or your relationship has a problem.
Of course I can't talk for all men. I can't be sure on what you mean by "A LOT of porn", nor how important porn is for him. All I can say is that masturbation is too common and it goes hand in hand with porn.
Have you ever asked him?