In this title, “domestic partnership” means a relationship between two individuals who: Are at least 18 years old; Are not related to each other by blood or marriage within four degrees of consanguinity under civil law rule; Are not married or in a civil union or domestic partnership with another individual; and Agree to be in a relationship of mutual interdependence in which each individual contributes to the maintenance and support of the other individual and the relationship, even if both individuals are not required to contribute equally to the relationship. An individual who asserts a domestic partnership under subsection (a) of this section may be required to provide: An affidavit signed under penalty of perjury by two individuals stating that they have established a domestic partnership; and Proof of any two of the following documents: Joint liability of the individuals for a mortgage, lease, or loan; The designation of one of the individuals as the primary beneficiary under a life insurance policy on the life of the other individual or under a retirement plan of the other individual; The designation of one of the individuals as the primary beneficiary of the will of the other individual; A durable power of attorney for health care or financial management granted by one of the individuals to the other individual; Joint ownership or lease by the individuals of a motor vehicle; A joint checking account, joint investments, or a joint credit account; A joint renter’s or homeowner’s insurance policy; Coverage on a health insurance policy; Joint responsibility for child care, such as guardianship or school documents; or A relationship or cohabitation contract.