The phrase suggests a non-traditional family structure where three individuals have established a committed, domestic partnership akin to marriage. This arrangement implies shared living space, potentially intertwined finances, and an emotional and practical interdependence beyond typical friendship. The dynamic can encompass a range of relationship configurations, from romantic entanglements between all three individuals to distinct paired relationships within the triad, or other agreed-upon arrangements.
Such living arrangements challenge conventional societal norms surrounding marriage and family. They can provide unique benefits, including increased emotional support, shared responsibilities in household management and childcare (if applicable), and potentially enhanced financial stability due to the pooling of resources. Historically, while legally unrecognized in most jurisdictions, polyamorous relationships, including those with three individuals, have existed in various forms across cultures and time periods. The increasing visibility and acceptance of diverse relationship structures are prompting ongoing discussions about legal recognition and societal understanding.