The reason for the cheating should also play a role in your discussions etc. Cheating doesn't happen in a vacuum. Yes, some people are serial cheaters and just flat out damaged, and probably shouldn't be trusted again but for many, if not most people, it is an anomaly....a psychological break from their normal personality and responses due to something.
In my husband's case, I am convinced it was due to clinical depression caused by severe stress (we had a business fail, which he thought made him a failure), which he had never experienced before.
My best friend cheated on her husband due to post partum depression. Prior to the PPD, such a thing would never, ever have occurred to her...I have known her for 25 years and I was stunned.