Play has important developmental benefits for young children that may be hindered or helped by their own emotional experience during play with others, such as parents, siblings, or peers. Our goal was to explore and examine the intersection of social interaction during play with temperament (i.e., social inhibition and negative emotionality) and age in connection with changes in emotional experience. Participants included 57 families with a child aged 3–5 years (46% female, M = 4.02 years, SD = 0.90) observed over 5 min using Ecological Momentary Assessment techniques. Results indicated that, in general, playing with parents and peers was linked to increases in positive emotions during play. Particularly when play partners were parents or peers, results demonstrated that positive emotions were moderated by social inhibition. Further, older children tended to display more negative emotion when not playing with a parent or a peer. The results of this study suggest that emotional experiences, particularly in the context of temperament and age, depend on the child’s play partner.