This chapter examines how toddlers develop affective relations while they play. A cultural–historical approach is used to understand affect and play. Visual methodologies are used to illustrate moments of affect in peer play. The case study involves two Australian-borne babies aged one and a half and two with Mexican and Chinese heritages, respectively. The case example analyses how transitory moments emerge when there are “affective moments of action”, as toddlers play together affectively and reciprocally. It is found that toddler’s affective actions are important in how they develop their play. Familiar games such as peek-a-boo, crawling like dogs and hop up and down like bunnies were played and shared in affective moments of action. These affective moments of action as transitory moments involved toddlers’ self-awareness of each other, change of actions and the sharing of multiple affective gazes and movements used to play collectively. Important implications for future research involve being aware of how peer play offers the exploration of toddlers’ will and agency and development of affective interest in each other’s play and games.