Bfs messages...

So I was kind of creeping over my bfs shoulder and I seen a lot of fb messages and even a message request... The problem I have with that is he use to talk to girls all the time behind my back and other stuff so I think it's messages from other girls, and he says it's just his family or something but he doesn't talk to many family Membes on Facebook or even friends. And a message request is from someone you're not friends with. For over a year he swears up and down he hasn't done anything with anyone or really talks to any othe girls and he only wants me which I believe but just because of past things I just haven't been able to let go of that so I don't really trust him that much either. Idk what to do. If I try to talk about it I know it'll be a fight, or him just ignoring me. It just put me in a bad mood cause I want to trust him but idek. No I can't just up and leave I do love him I've been with him for a long time and I live with him. But I just question a lot of things honestly...