Sketched out

I need somewhere to vent about this situation and thank god I remembered about eve.. my boyfriend talks to his ex gf over Snapchat and typically closes whatever he is doing on his phone when I come to sit near him. I’ve brought it up before he said he wasn’t doing it on purpose it was just what he did. I didn’t know he still talked to his ex.. the last I heard was that he was upset with her n just couldn’t handle her anymore. My boyfriend and how I am with him is how he was always been with her. One time I even told him I wish I you weren’t my Jessica. Bcs that spot in my heart for him is insanely much and I don’t think it’s the same way with him. He asked me to move in recently and I did. We dint go through each others phone or anything I’ve told him how I feel about the phones n my paranoia with them.. I know I’m insecure and I just don’t know how to handle seeing that they still fucking talk.. any tips on what I should do to get over it ?