Bf lying

So my bf has cheated in the past but he hasn't in the last year now so I thought we were past this whole ordeal.... anyways I noticed that he's always taking his phone with him everywhere so one night I went through it and there was nothing but I decided to go through his "files" which is basically his storage and there's where I found everything. He straight up took screenshots of girls off instagram in there bikini but he some how talked me back into forgiving him again and said i can go through his phone whenever. So last night I said I'm gonna go through your phone and he's like it's dead you can in the morning. So I'm like okay but started to think about it.. why is it so hard for me to charge his phone and go through it? He has an android so when you plug it in it turns on almost instantly.. I just forgot about it at that point and went to bed. So this morning I woke up to pee and saw his phone on the ground by his shorts and pressed it and it WAS ON. He totally lied to me and I honestly think he's hiding shit now. I made it very clear to him that if he doesn't let me go through it then I'm out of his life. Im seriously thinking of leaving today. The only thing I can think of is he didn't delete the shit out of his files because I literally only saw one girl he screenshotted and didn't even care to look at the rest and that same day I did I asked to see all of it and he's like I deleted it all. Idk what to do...