"What do you like to watch?" "Your mom."
I'm kinda curious about your generation. I was in high school 20 years ago, and I was one of the very few kids savvy enough to have access to such content. Back then, most kids my age only had access to their dad's stash, so this topic of conversation wasn't really a part of my childhood. I suspect that suzi and I interpret this as much more intrusive than your average boy does today. I'd personally take advice from oldsters like us with a grain of salt... but here goes nothing.
I guess the question is "do you want to fit in with boys while you're still in the closet?" If you don't, then your answer won't matter much. Just say "I'm not into that" or "that's gross, get away from me" or something along those lines.
If you do, then it can be tricky. You can blame your parents. They check on your browser history and your phone, so you don't watch it. You can say something that's on the boundary of truthfulness, "I don't need porn to get off".