Is it normal to feel aroused differently by porn that by a partner?

Hey there, I'm in my early twenties and have been with the same guy for two years now. He suggested we watch porn together but I realized it makes me uncomfortable, even though I like to watch it by myself. I think it's because sex with my bf feels more emotional, and I like porn because it's just a quick way to get off and I'm focused only on the images. I feel a different type of arousal with each. Is this normal?