In adopting new theoretical advancements within linguistics and ecological psychology, this paper investigates humor from an ecological perspective in naturally occurring social interaction. In doing so, it is claimed that the notions of language as coordination and values-realizing can provide a new understanding of humor as it appears in human interaction. This argument will be unfolded as a rethinking of Wallace Chafe’s notion of nonseriousness (Chafe, 2007) that re-conceptualizes Chafe’s idea of a ‘mental state’ of nonseriousness in terms of interactional affordances and values realizing. This perspective is laid out in in-depth analyses of video recordings of two real-life examples from different settings: two siblings playing and a sequence from a couple-therapy session. It is claimed that both examples of interactional humor can be explained by re-conceptualizing humor as a distinct way of being together. Thus, the emergence of humor is enabled by a shift in the coordinative dynamics rather than by a transfer of semantic ‘content’ from a speaker to a hearer. Finally, humor is investigated as a temporal phenomenon integrating immediate ’here-and-now’ environmental features with socio-cultural expectations on a longer time-scale. In this way humor is viewed as a particular type of values-realizing activity that constrains our actions, re-directs our attention, and thereby enables us to act in a more playful and joyous manner.