(1) An adult commits an offence if the adult has sexual intercourse with a minor who—
(a) is the adult's adopted child, step-child, foster child, ward or dependant; or
(b) not being the adult's adopted child, step-child, foster child, ward or dependant is at the time of the intercourse living with the adult as a member of the family or is under the adult's care or protection.
(2) It is immaterial that the sexual intercourse referred to under subsection (1) occurred with the consent of the minor.
(3) A person who commits an offence under subsection (1) is liable on conviction—
(a) if the minor is under the age of 12 years to imprisonment for life; or
(b) if the minor is 12 years of age or more to imprisonment for 25 years.
(4) An adult is not guilty of an offence under subsection (1) if the minor is the spouse of the adult.
(5) If a marriage is declared invalid by a Court of competent jurisdiction the invalidity does not make a person guilty of an offence under this section because that person has sexual intercourse with a person who he or she believes to be his or her spouse, and has reasonable cause for the belief.