This research examines one lead teacher's and two assistant teachers’ emotional discomfort as they participated in an eight-month collaborative ethnography of 19 children's peer-culture aggression in an early care and education classroom in the USA. Two questions guided this analysis: (1) What are the emotional themes of teachers in relation to children's peer-culture aggression? (2) How did the teachers utilize an ethic of discomfort when responding to children's peer-culture aggression? Collaborative ethnographic procedures, along with a post-structural account of teacher emotion, were used in a qualitative thematic analysis to determine salient themes and patterns. The data consisted of participant observation, field notes, video recordings of children's play, audio-recorded teacher team meetings, classroom artifacts, informal discussions, and a data-revisiting journal. Over the course of the study, the three teachers moved from resistance to emotional discomfort with children's peer-culture aggression, to a less resistant and more reflexive position toward emotional discomfort and child aggression. This shift occurred as the teachers began to release the goal of certainty and instead acknowledge and accept the unknowing and complexities associated with an ethic of discomfort. The implications center on the importance of teachers’ openness to “staying with” emotional discomfort, as well as making time and space to uncover a range of teacher and child emotions.