21. a. Any agreement in writing to furnish support for a child, growing out of a supposed or alleged father and child relationship, does not require consideration and is enforceable according to its terms, subject to subsection d. of section 8.
b. In the best interests of the child or the mother, the court may, and upon the request of the person agreeing to furnish support shall, order the agreement to be kept in confidence and designate a person or agency to receive and disburse on behalf of the child all amounts paid in performance of the agreement.