The problem with trust
You never really know how strong of a relationship you have with someone until that trust is tested. The problem with trust is that once it's broken, it's hard to build back up to the same level of trust. It's much much easier to suspect the worst of somebody than to have faith in them. So if you think about it, it takes both sides to really rebuild from a betrayal of trust. If one person takes all of the blame, but the other person doesn't truly forgive them, then there is an imbalance in the relationship that will inevitably come to a head at some point. At the same time, it's not like you can't just have it all out at once and push the reset button. It's almost impossible to forget about everything that happened beforehand and start fresh. That's just not how most people are. There needs to be some time for healing and recovery. But given enough time and the effort of two people who really desire it, I think you can rebuild a broken trust to be even stronger than it was before. The only problem there is determining who is actually worthy of that time and effort. What's the point in building a bridge if it only goes one way?