Whether porn is good or bad depends on the person. I have seen marriages destroyed by porn addiction. I have seen some marriage flourish with it. It all depends on the person. When it gets out of control and you can't live without it or it takes the place of your wife, husband, boyfriend or girlfriend it is a problem. When you start watching it at work it is a problem. When you are hiding it from you significant other it's a problem. As an ex porn addict I know what damage it can do to a relationship. I still have to watch carefully when I get angry or hurt for it is easy to fall back on porn as a crutch.