cheating???

I want to know if hes cheat(ed/ing)on me. I dont want to invade his privacy and go through his phone though. My past relationships all eneded bad, because the guy would cheat on me or leave me for some new shiny thing. I know thats not my current boyfriend's problem, but im scared hes going to leave me. I really love him too, I am taking a leap and hoping that he loves me the way he says he does. What can i do to figure this out or get over it?!?!?