Trust is so key in any relationship-but even more so in an open relationship.
Maca and I were discussing this just yesterday, he struggles with trust. I don't so much.
The key difference in our perspectives is that I don't stop trusting just because someone hurts me. My trust is based in the INTENTION. Did they INTEND to hurt me? If not-then there's no need to lose trust in them, we all make mistakes. Where as he trusts those who don't hurt him at all. Unfortunately for him, given time everyone will hurt you at some point.
"Love As Thou Wilt"