Trust is built in very small moments, which I call sliding door moments. These are moments where we have a choice to connect with our partner or turn away from them. For example, I once had a moment where my wife was brushing her hair in the bathroom, and I could have chosen to ignore her sadness or connect with her. I chose to connect with her, and that moment built trust in our relationship.
The mechanism of attunement is the basis for building trust. This involves being aware of our partner's emotions, turning towards their emotions, tolerating different viewpoints, going for understanding, responding non-defensively, and responding with empathy.
Betrayal and distrust are not strongly related. Betrayal is not just about turning away from our partner, but also about having an internal monologue that goes something like 'I can do better'. This internal monologue can lead to a cascade of negative thoughts and behaviors that damage our relationship.