same-sex marriage(n = noun.group) - two people of the same sex who live together as a family; "the legal status of same-sex marriages has been hotly debated"
is a kind of couple, duet, duo, twosome

civil marriage, common-law marriage, dissolution of marriage, marriage, marriage bed, marriage broker, marriage brokerage, marriage ceremony, marriage contract, marriage counseling, marriage licence, marriage license, marriage mart, marriage of convenience, marriage offer, marriage proposal, marriage settlement, mixed marriage, open marriage, outside marriage, proposal of marriage