(a) A married person may make contracts, oral and written, sealed and unsealed, with the married person’s spouse, or any other person, in the same manner as if the married person were sole.
(b) An agreement between spouses providing for periodic payments for the support and maintenance of one spouse by the other, or for the support, maintenance, and education of children of the parties, when the agreement is made in contemplation of divorce or judicial separation, is valid; provided that:

(1) The agreement shall be subject to approval by the court in any subsequent proceeding for divorce or judicial separation; and
(2) Future payments under an approved agreement shall nevertheless be subject to increase, decrease, or termination from time to time upon application and a showing of circumstances justifying a modification thereof.
(c) All contracts made between spouses, whenever made, whether before or after June 6, 1987, and not otherwise invalid because of any other law, shall be valid.