Guys: is it normal for boyfriend to watch porn during sex?

I understand all men watch porn... but something happened that really sort of upsetted me. I know im an attractive 27 year old girl and im not ugly by any means. I've been in an on and of relationship for about 3 years. Sex with us is amazing and im always tryin to find little ways to spice it up. However, my boyfriend is the type who always needs to be in control so really he's doing all the work... so one time while we were having sex, he grabs ahold of my phone and starts looking at porn AS he's havin sex with me, I mean when I was going down on him he was just staring at the porn the whole time instead of looking at me. I didn't even know what he was doing, I thought he was recording me but I snatched the phone from him...I was mad and he just told me to get over it and that im no fun. So whats going on, I know im not ugly and I don't think he thinks I am, or does he? I just think if he's really into me he shouldn't be looking and getting turned on by another female. Guys, gentlemen, do I havea a right to be upset or am I overreacting? What's going on inside the males brain.