In this chapter, I explore understandings and practices of ‘open’ and ‘closed’ sociality played out in a children’s sports project in an inner-city neighbourhood in Copenhagen, Denmark. In keeping with government policies promoting social integration through sports, an Open Gym project was sponsored by the Copenhagen branch of the Danish Gymnastics and Sport Associations (DGI) to channel ‘associationless’ children into local sports associations and through these into ‘local society’. The following discussion grew out of trying to understand why Open Gym was not made a permanent activity when inner-city children often came, enjoyed themselves and certainly obtained the exercise health experts felt they so badly needed. I argue that while the relationally open venue of Open Gym did not pose any unsurmountable problems for children’s participation, it did create relational ambiguity and uncertainty among adults responsible for its daily running. Exploring the relational dilemmas this open venue posed for adults, I conclude that the key to understanding the demise of the successful (seen from a child’s perspective) recreational activity lies in dominant notions of ‘closed’ public sociality that require a particular set of exchange relations between domestic and public caretakers. Despite Open Gym’s success as an activity venue for neighbourhood children, it could not be placed within the dominant system of generational relations thought to constitute ‘local society’.