Opinions

So my boyfriend and I have been together for 2 1/2 years and we are going to be getting our own place together soon. We know we want to get married and have kids in the near future. However, he's a little older and he's been married before. He divorced about 4 years ago after she cheated on him. She's asked him to get back together a few months ago and he said he chose me, but I found a written letter from that same date that he ran into her and they had that conversation, and the letter said how much he loves her and how he will do anything to get her back in his life and no other girl compares to her and that he had a long talk with me about his true feelings (which he didn't). I was devastated so I confronted him and he said he never sent that to her it was meant to be like a diary. I just don't understand it. And now that we're moving out of this house (where we live with roommates, but it's the house that he and she had bought together when they first got married) he doesn't want to throw away any of their pictures together. And their old things are bringing up old memories which I understand. I understand they were together for a long time and she is a big part of his past. But I'm not going to be living in our own house with him and getting married and having a family when he still has all these old pics of them buried in the closet. Even on Facebook he won't delete all their pictures and he says it's because she was a big part of his past. I get it! But it's time to move on. I'm happy we're getting out of this house because I wouldn't feel comfortable raising a family here when it really holds the value of being "their" house. He says he agrees and he's happy for a new start. But I feel like he's never truly going to get over her and it's upsetting me. What do you ladies think? Am I overreacting? Should he be getting rid of their pictures and things? How do I get him to do it because I'm ready to just rip them all up myself. But I don't want to be mean, he already got mad at me because he thought I threw out a picture of them and he acted like he was ready to go dumpster diving for it and this said picture didn't even exist.