For more than four decades, studies of higher education have espoused the significance of fostering intercultural interactions between international and domestic students, yet numerous studies have provided widespread evidence of limited interactions between these cohorts and limited development of long-lasting relationships, such as friendship. After reviewing the conceptualisations of intercultural relationship development and their limitations in the extant literature, this paper outlines the rationale for a three-stage ecological and person-in-context conceptual framework of the development of intercultural relationships in university contexts. The proposed framework addresses: the issue of loose conceptualisations of intercultural relationships in the literature; the overlooked phenomena of dynamic interactions between individual and environmental dimensions that co-contribute to intercultural relationship development; and the developmental nature of intercultural relationships. The main proposal underpinning the framework is that the development of intercultural relationships occurs at the dynamic experiential interface between environmental affordances and students' agency, both of which evolve along three stages of relationships (i.e. interactivity, reciprocity and unity). The framework, illustrated by empirical data, addresses aspects of intercultural relationships that have been neglected in the higher education literature, and that are expected to stimulate further educational research and practices in various (inter-)national/regional and institutional contexts.