If the union of men and women is based on love, then both men and women can live together and form a happy family as long as they love each other and love each other.
Because they love each other, they will wholeheartedly serve each other, respect, care and love each other. They don't have to worry that the other party will cheat and betray them.
Although sometimes there is a little friction and a little temper, they are so steadfast in their love for each other, and soon the power of love will dissolve the small contradictions between them and make them more closely together. As if it were a person.
From this point of view, the marriage law is not necessary for them and is completely useless.
They don't need a marriage law to define their rights and obligations, because they know what they have to do to make each other happy.
They don't need the marriage law to "insure" their love, because when they have this idea, the love between them is actually "uninsured".
Likewise, they don't need a marriage law to prevent a third party from interfering, because if they can allow a third party to intervene, then the marriage law can't prevent it.
Visible, true love does not apply marriage law. Once the law of marriage works among them, there may be no love between them.