Cheating boyfriend

My (ex) boyfriend and I have recently broken up. He had sex with another girl over the thanksgiving holiday (we were in a relationship then) He told me he cheated that following Monday through a text while I was taking an English final. We have had long talks since then. He's came to church with me and brought me flowers and such. He has talked a lot with my parents and his mother has reached out to me apologizing for him. I think he is genuinely sorry about what happened but I don't trust him. Any advise?