Incest is marriage or sexual relations between close relatives. The criminal offense of incest may also be known as prohibited sexual conduct. Laws vary from state to state, but incest laws generally prohibit marriage or sexual relations between (1) a person’s ancestor or descendant by blood or adoption; (2) a person’s current or former stepchild or stepparent; (3) a person’s parent’s brother or sister of the whole or half blood; (4) a person’s brother or sister of the whole or half blood or by adoption; (5) the children of a person’s brother or sister of the whole or half blood, or by adoption; or (6) the son or daughter of a person’s aunt or uncle of the whole or half blood or by adoption.

Lack of consent to sexual relations between such relatives is not an element of the crime, and persons may be guilty of the crime even if both parties consented.

Laws regarding incest or prohibited sexual contact vary from state to state and are generally located in a state’s statutes—often in the penal or criminal code. The crime is a felony offense in many states, with potential punishment of significant jail or prison time.

In Maine, incest is defined as sexual intercourse between persons who are first-degree relatives, such as a parent and child or siblings, whether by blood or adoption. This also includes sexual relations between a person and their ancestor or descendant, stepchild or stepparent, uncle, aunt, nephew, or niece. Maine law considers incest a Class C crime, which is a felony. The fact that both parties may consent to the sexual relationship does not absolve them of criminal responsibility under Maine's incest laws. Conviction of incest in Maine can result in significant penalties, including imprisonment. It is important for individuals in Maine to be aware of these regulations to avoid legal repercussions related to prohibited sexual conduct.