In all prosecutions under § 25-7-4 or under §§ 25-7-16 to 25-7-20, inclusive, any existing provisions of law prohibiting the disclosure of confidential communications between husband and wife shall not apply, and both husband and wife shall be competent to testify to any and all relevant matters, including the fact of marriage and the parentage of a child or children.
SDCL 25-7-22