The (im)possibility of legal recognition of simultaneous families in the Brazilian legal system in light of Supreme Court case 529

Abstract

This paper analyzes the (im)possibility of the legal recognition of simultaneous families in Brazil, in light of Topic 529 of the Supreme Federal Court (STF). The study highlights the transition from the patriarchal and monogamous model to an approach that values family plurality, especially after the 1988 Federal Constitution and the 2002 Civil Code. Constitutional principles applicable to Family Law are discussed, such as dignity, equality, affection, solidarity, and family plurality, emphasizing the need for the legal system to adapt to new social configurations. The distinction and convergence between marriage and stable union are analyzed, as well as the emergence of simultaneous unions, characterized by the coexistence of multiple stable affective bonds, even if legally unrecognized due to the prohibition of bigamy and the principle of monogamy. The STF's ruling on Topic 529 reaffirms monogamy as a structuring principle of Brazilian Family Law, resulting in the legal invisibility of simultaneous families. However, doctrine and some case law point to the need for legislative revision in order to encompass affective diversity and guarantee legal protection for relationships based on loyalty and affection. It is concluded that, although the legal system remains centered on monogamy, it is imperative that it adapts to new family realities, promoting a balance between affective freedom, family pluralism, and legal security.