(a) A promise in writing to furnish support for a child, growing out of a presumed parent or alleged father and child relationship, does not require consideration and, subject to Section 7632, is enforceable according to its terms.
(b) In the best interest of the child or the other parent, the court may, and upon the promisor’s request shall, order the promise 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 promise.