<P> Group marriage (a form of polyfidelity) is a marriage - like arrangement between more than two people, where three or more adults live together, all considering themselves partners, sharing finances, children, and household responsibilities . No claim to being married in formal legal terms is made . </P> <P> The term reentered popular consciousness in 1974 with the publication of Group Marriage: a study of contemporary multilateral marriage by Larry Constantine and Joan Constantine . </P> <P> Depending on the sexual orientation and activity of the members, all adults in the family may be sexual partners . For instance, if all members are heterosexual, all the women may have sexual relationships with all the men . If members are bisexual or pansexual, they may have evolved sexual relationships with either sex . </P> <P> Group marriage implies a strong commitment to be faithful by only having sex within the group and staying together longterm . The group may be open to taking on new partners, but only if all members of the family agree to accept the new person as a partner . The new person then moves into the household and becomes an equal member of the family . </P>

How many relationships are possible in a group of five