This article problematises traditionalist thinking in constitutional adjudication in relation to the rights of same-sex couples, especially those rights that are connected to family life. It identifies two approaches, represented respectively by the case law of the Italian Constitutional Court (ItCC) and the Court of Final Appeal (CFA) of the Hong Kong SAR of the People’s Republic of China. The ItCC has expressly stated that preserving traditional family forms is a reasonable objective per se for the legislature to pursue. The CFA, on the other hand, has challenged this approach to traditionalist thinking in relation to same-sex unions. Despite some contradictory signals within its case law, the CFA has stated that justifying differential treatment based on sexual orientation with reference to tradition is circular reasoning. Drawing on historical, anthropological, and philosophical sources, this article argues that invoking the preservation of tradition, despite its rhetorical force, is empirically and conceptually criticisable and, ultimately, unpersuasive.