Is it wrong that I don't like my boyfriend watching porn?

We've been together 3 years. Early in our relationship, I would always find porn on his phone. It always bothered me and made me feel like he was mentally cheating on me. However, it stopped, or at least he got good at hiding it from me for about a year! Yesterday he had me look something up on his phone. When I was done, I closed the page and saw there were 2 other pages of porn open on his phone. I just nonchalantly told him that he left his porn up and handed his phone back. I was immediately hurt. He's not the kind of guy who needs to look at other girls, so it makes me feel like I'm not good enough. I told him I was hurt, and remained quiet for the rest of the night. He told me he was sorry that it hurt me, but that I'm taking it too much to heart. He just called it a "jerk off aide" and basically said I shouldn't be mad at him. I know every guy watches porn, and I know I can't make him stop. But is it wrong that it upsets me when he watches it? How would you feel?