(a) The court may grant an annulment of a marriage to a party to the marriage on the suit of the party or the party's guardian or next friend, if the court finds it to be in the party's best interest to be represented by a guardian or next friend, if:
(1) at the time of the marriage the petitioner did not have the mental capacity to consent to marriage or to understand the nature of the marriage ceremony because of a mental disease or defect; and
(2) since the marriage ceremony, the petitioner has not voluntarily cohabited with the other party during a period when the petitioner possessed the mental capacity to recognize the marriage relationship.
(b) The court may grant an annulment of a marriage to a party to the marriage if:
(1) at the time of the marriage the other party did not have the mental capacity to consent to marriage or to understand the nature of the marriage ceremony because of a mental disease or defect;
(2) at the time of the marriage the petitioner neither knew nor reasonably should have known of the mental disease or defect; and
(3) since the date the petitioner discovered or reasonably should have discovered the mental disease or defect, the petitioner has not voluntarily cohabited with the other party.