Trust means that after the boundaries are defined, then not to cross those boundaries. When you stay within the boundaries as defined in a relationship, it means you are maintaining trust. Some boundaries are spoken, others are understood. You have to define this yourself with the other person.
When you trust the person, you don't have the need to control the person. So, you give space. You allow freedom in the relationship. Because you are secure in the trust. Giving space leads to healthy relationships. It shows you are flexible to accept the person in any form. Hence, no need to control, and hence through this security you give space.
A real relationship is built on trust and space.