It's crucial to figure out why you cheated in the first place in order to prevent it from happening again. For example, after a few weeks of therapy post ex-breakup, it became clear to me that one of my biggest emotional triggers is when someone cancels plans on me at the last minute. So, in my current relationship, I communicated my need for reliability early on. Now, when plans do change, as plans are wont to do, my boyfriend makes it clear that he's not blowing me off. I am better able to reassure myself that he loves me, and the world spins madly on.