I want to look at my boyfriends computer

I want to look at his computer to see if he's watched porn on it recently. I told him that that is one of my deal breakers and that if he watched porn I will leave. It's just something that I'm against. (I don't care if you're not against it, I am). But I'm afraid he has some screen recording on it or something. He never leaves it on with me around and he's also super weird about his phone. Never leaves it around, holds it away from me, etc.

*i don't often look through his things, this will be my second time and I've never looked through his computer