This is serious. He has a problem, just like any other addiction. It does not make him a bad person, it just makes him one that needs help. There are several things that this can lead to if left untreated. Insist that he seek help.

Porn is only the beginning. This can lead to more serious offenses.

Once addicted to porn, normal arousal in a heterosexual monogamous relationship decreases until it ceases to exist. Many older men suffer from erectile dysfunction as a direct result to an over active and over stimulated sex life early on.