Mutuality is submission. We belong to one another. Each submits to others, each seeks welfare of others. Must know, be known. Implies there is no human hierarchy.
Mutuality means no manipulation, coercion, only willing service.
Mutuality is possible because in following example of Jesus Christ who served, we empty self, consider selves as nothing. How much can I be like Jesus who is my example, Phil. We hear much about love today, yet misunderstand. Often love is mushy, oozing, useless. Real love serves, submits, gives, as in John 13.