Multi-sited ethnography has been extensively applied to migrants' transnational family life and to the underlying care practices. Its methodological underpinnings and dilemmas, though, are relatively under-reflected. How can the relational and affective spaces between migrants and left-behind kin be ethnographically appreciated? Against this question, I revisit my fieldwork on a migration flow between Ecuador and Italy. This is an instance of the development of transnational social relationships, based on the circulation of material, cognitive and emotional resources, whereby people living 'here' and 'there' negotiate mutual affections, concerns and expectations. The challenge for ethnographers, under similar circumstances, lies less in staying in more sites than in sensing and understanding the relationships between them and the social practices on which this connectedness relies. The attendant methodological implications are discussed, ultimately pointing to the significance of relationality and in-betweenness for ethnographies of migration, transnationalism and mobilities.