Since the early 1990s, economic exchanges between China and Taiwan have paved the way to migration across a previously closed border and to social and cultural interactions between the two populations. Despite these broader changes, the unresolved issue of Taiwan sovereignty has tainted not only the relations between the two governments but also the everyday life of those who move across the Taiwan Strait. In this politicised environment, intimate and affective practices linked to cross-border marriage and family formation are never just private. Instead, they are deeply entangled with the emotional and affective processes generated at the macro and meso level of political and social life and revolving around national interests. Tracing the intimate, emotional and affective practices linked to family creation, identity formation and integration with the local and national communities, this ethnographic study offers a subjective, dynamic, and complex picture of what it means to be a mainland spouse in Taiwan.