9 GCA § 31.15: Incest: Defined & Punished.

A person is guilty of incest, a misdemeanor, if he knowingly marries or cohabits or has sexual intercourse with an ancestor or descendant, a brother or sister of the whole or half blood or an uncle, aunt, nephew or niece of the whole blood. Cohabit means to live together under the representation or appearance of being married. The relationships referred to herein include blood relationships without regard to legitimacy, and relationship of parent and child by adoption.