Well, I hate to say it ladies, but I think women get too worked up over porn.
Guys are, by their nature, extremely horny, and they will look at porn to relieve that sexual pressure. Most women I know simply can't comprehend the fact that guys masturbate frequently. It shouldn't be a reflection of the relationship or make you feel like you are inadequate. I know women can feel like crap when they find out their guy has porn and/or masturbates because you think that you aren't good enough. That's not it! We make a very clear and total distinction between looking at porn and loving our woman.
Besides, if you try to ban porn in the house, he'll get it one way or another.
It's probably best to just talk about it with your guy. Don't do it in a way that makes him defensive. Ask him why he likes porn. Be honest with each other, but also try to understand his point of view. A friend of mine had some porn on his PC and his wife went bonkers - even threatened a divorce. That's the best way for you ladies to prevent your man from ever discussing the issue with you. From then on he'll just hide it and lie if you ask about it. Is that what you want?
Just my 2 cents.