I have had this issue as well. At first, I did feel as you do. I was hurt and took it personal. When I asked him, he also said it had nothing to do with me, most guys do it, etc. I was very naive on the subject so I read what I could and found that it is pretty common.
Without putting him on the defensive, I just told him how it made me feel. After a week or so and reading up on what I could, I put it into a different perspective...if he is a visual person with sexual urges throughout the day, I would rather have him deal with it looking at a screen vs. anything in the real world. I talked to him about that and basically said I'm ok with it as long as it's you just looking (no chatting with other women, etc.) and as long as it doesn't interfere with us (our time together our sex life, etc.) but if you find yourself getting out of control with it where you need it more often or more explicit that you deal with it...He said, too late I deleted it all and don't plan to look at it...this was a year ago and if he does it at all it is minimal.
To answer your question, I don't think you should just let it go. If your feelings are not being validated it may cause you to build resentment towards him. Letting him know in a way that doesn't make him defensive...meaning just talking about your feelings might be the best approach vs. making demands, etc.
It helped me to validate what he said followed by how I was feeling "you know, I checked around and did find that most guys do look at porn which made me feel a little better. What really hurts me about it is that it makes me feel like you are looking for something better or that I'm not enough. The other thing I read was that it's easy to get bored with it and over time it can get more explicit or become an addiction and I'm worried about that too...I guess I just want you all to myself

" will probably work better than "If you love me you will stop for me" or "how can you put looking at naked women above my feelings" because he is not on the same page and doesn't see a problem with what he's doing and thinks you are overreacting (I don't think you are by the way)