<human>: Can you condense the text into three sentences or less?

Bsckstory: We've been together for 2 years. I'm not a very trusting person and have extremely low self esteem. 
When we first met, he was the type to have a bunch of dirty pics on his phone, followed all the naked pic accounts on Twitter but besides that we were extremely compatible. He knew how uncomfortable I was with all that so he deleted and unfollowed everything and we got way closer and I eventually began to feel really secure/good about myself with him. But tonight he was laying down at the other side of the bed and his phone went off. He picks it up, opens the text, looks at it, looks back to see if I'm sleeping and then opens each photo to fullscreen. I even saw him save one! I immediately react, obviously I'm upset, and all he says is that is dumb friend sent them to him and to just go to bed. 

I'm completely crushed. I know this wouldn't bother some people but I've always felt really insecure about these kinds of things and just the thought of these pictures on his phone makes me sick to my stomach, specially since I've put so much trust in him about it, maybe too much.

He's just going to blow me off about it. How should I go about this? I'm not okay with lying and hiding things. Because he was like this 2 years ago, could it possibly be "that guy" coming out again? I don't know what to do!
<bot>: caught boyfriend opening texts with dirty pics and saving them. He knows I'm extremely insecure about it and don't know what to do now.