Think of this before you start self-sabotaging and driving the wedge you now have between the two of your even farther in: You will have a very hard time finding a man that doesn't not masturbate to some sort of visual aid. A very hard time so perhaps you would be better off if you asked him to go to some form of couples counceling so that you both can learn to meet each others needs in a more mature manner. He's apathetic and you're insecure by thinking that the women of porn are some kind of threat to you. Both those isses need to be addressed by an unbiased, professional third party.
If you leave him without addressing your own issues, then the problem will just surface again in your next relationship.
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion