Without application for a divorce, the husband or the wife may bring an action for the exclusive control of the children of the marriage; and the court may, during the pendency of such action, or at the final hearing thereof, or afterwards, make such order or decree in regard to the support, care, custody, education, and control of the children of the marriage, as may be just and in accordance with the natural rights of the parents and the best interests of the children, and may at any time thereafter amend, vary, or modify such order or decree, as the natural rights and the interests of the parties, including the children, may require.

SOURCE: CC § 199.