I am going to play 'devil's advocate' on this issue.

To HER, you are being faithful. You told her you wouldn't use porn and you did (a trust issue).

Plus, you have to look at it from HER point of view...if you are using porn, she might think 'I am not enough for him. He is atracted to the women in the magazines, not me.'

That being said, if the two of you are going to be together, she has to realize this is a real 'addiction' for you. You WILL lapse but it doesn't mean you love her any less.

Are you extremely affectionate with her?
Does she have any other reason to feel threatened?
What do you get from the magazines that you don't get from her?

These are ALL rhetorical questions for you and not meant to be answered HERE! (Frankly, it's none of our business.)

Just showing you the 'other side'. Maybe if you understand why it hurts her, it can help fuel your recovery from the addiction and avoid a lapse.