Based on thorough ethnographic descriptions, this article analyses retirees’ collective activities in Beijing public parks where co-presence and interactions between formerly unacquainted individuals have evolved into achieved relations of familiarity and friendship. Focusing on how people define, enact and manage the relationships with those they ‘have fun’ with, I show that the forms of mutual knowing developed through joint participation often blur the boundaries between the private, parochial and public realms on the one hand, and between community and anonymity on the other hand. While the urban experience in the Chinese context has been viewed as constituted through both ‘face’ (i.e. communitarian) and ‘faceless’ (i.e. anonymous) interactions, I argue that these are but two conceptual poles which cannot exhaust the complex nature of social relationships that arise from urban encounters. Activity-orientated friendships in Beijing parks involve wide-ranging forms of mutual knowing, which shape a pleasurable urban experience as much as they are infused with the ‘ethics of indifference’ peculiar to city living. As retirees initiate and sustain pleasurable interactions, these forms of sociality do not entail tight reciprocal commitments. Instead of viewing the situations in which friendships are produced as an instantiation of the ‘broader contexts’ in which they are embedded, I suggest that these everyday spatial practices and convivial interactions should be considered for their intrinsic analytical value rather than as a response to external processes.