In a divorce action for adultery, the following defenses may be made:
(1) procurement;
(2) connivance;
(3) the act has been expressly forgiven or impliedly forgiven by the voluntary cohabitation of the parties after knowledge of the act;
(4) the plaintiff is also guilty of adultery and without procurement or connivance of the defendant and not forgiven as provided in the defenses to adultery; or
(5) the action has not been commenced within two years after the discovery of the act by the plaintiff.