Accessible summary In Belgium some adults with learning difficulties live with their siblings and siblings‐in‐law. The authors of this article listened to siblings‐in‐law, trying to understand how they felt about this living together. This article seems to be important for those persons with learning disabilities who give a lot about their sisters and brothers. Summary There is a lack of international research focusing on how the siblings‐in‐law of adults with a learning disability experience their commitment to provide support. Using narrative research, the authors have aimed to gain an insight into the perspectives of 14 siblings‐in‐law (living in the Flemish part of Belgium) about the decision to live together with a family member who has a learning disability. The decision to live together usually begins with a crisis. However, the decision process is a complex mechanism; it involves dynamics and events within a family (between family members both with and without blood relationships) and is intensified by experiences within a society that holds different views about families and disability. We are aided in gaining a deeper understanding of this complex process by considering interpretations based on the contextual framework of Boszormenyi‐Nagy.