As a consequence of their size and fragility, small groups depend on cohesion. Central to group continuation are occasions of collective hedonic satisfaction that encourage attachment. These times are popularly labeled “fun.” While groupness can be the cause of fun, we emphasize the effects of fun, as understood by participants. Shared enjoyment, located in temporal and spatial affordances, creates conditions for communal identification. Such moments serve as commitment devices building affiliation, modeling positive relations, and moderating interpersonal tension. Further, they encourage retrospective narration, providing an appealing past, an assumed future, and a sense of groupness. The rhetoric of fun supports interactional smoothness in the face of potential ruptures. Building on the authors’ field observations and other ethnographies, we argue that both the experience and recall of fun bolsters group stability. We conclude by suggesting that additional research must address the role of power and boundary-building in the fun moment.