Boyfriend (again) hiding porn

So once again, I found strange porn on my SO's phone. Last time I found gay porn on his phone but he deleted it the day after I found it, so I never bothered confronting him because I knew he'd deny it. This time, I found 'jailbait' porn. (It was legal). The main reason I'm bothered by this is I was trying to get him to have sex with me, but he would rather wait until I go to bed to watch porn. And weird porn at that. I don't understand. I just want him to open up to me and talk about these things but he won't. How can I get him to open up?