I found my (21f) boyfriend (22m) hidden camera roll of girls revealing photos. Help

My boyfriend and I have been together for almost a year. I found my boyfriend's hidden photos in his camera roll a couple of days ago. It was full of screenshots of girls he personally knows Instagram bikini pictures, and other revealing photos of these girls. Most of the girls were girls he had past feelings or relationships with, which makes me even more uncomfortable. This was also shortly after I found out he was secretly looking at OF girls (even after I told him I was uncomfortable with it). When I confronted him about these secret photos, his only answer was that he didn't know why he did it and he didn't know why he didn't delete them. I find this very disrespectful not only to me, but to these girls as well. I don't understand why'd he go behind my back and screenshot these revealing photos of women he personally knows and keep them in a hidden folder. It feels very wrong to me and I'm so upset. We have been together for a little over a year and he's been nothing but perfect, so all of this is very shocking to me. I'm at a loss of what to do. Do I leave him? Do I stay and pray he never does this weird behavior again? I don't know what to do.