Am I wrong for not giving in?

My boyfriend and I tried to have anal sex once and I couldn't go through with it. I know a lot of it is relaxing (I was tense as hell) and I'd assume a ton of lube (and we had none). One day, I was using his tablet and saw all in his browser history a bunch of anal porn videos. He didn't make a big deal about me backing out of doing it but after seeing all the porn he's been watching has me a little worried he will look for someone who WILL enjoy it. Am I being paranoid or should I suck it up and give it another chance for him?