Spouse, as defined in the statute, means a husband or wife. For purposes of this definition, husband or wife refers to the other person with whom an individual entered into marriage as defined or recognized under state law for purposes of marriage in the State in which the marriage was entered into or, in the case of a marriage entered into outside of any State, if the marriage is valid in the place where entered into and could have been entered into in at least one State. This definition includes an individual in a same-sex or common law marriage that either:
(1) Was entered into in a State that recognizes such marriages; or
(2) If entered into outside of any State, is valid in the place where entered into and could have been entered into in at least one State.