This article highlights the interactional work involved in relational aggression, and how rules and norms around sitting are used by students to achieve exclusion and dominance. This research took place in an English secondary school which educates pupils from Year 7 to sixth form (ages 11–18). Drawing on observation, walk-and-talk and group discussion data with Year 9 students (age 13–14), this research highlights how the girls developed shared rules and norms around sitting which, while seemingly reasonable and applied equally to all, are seen to facilitate and legitimise exclusion and relational aggression. Girls from different social groups collaboratively constructed and participated in a system of rules which were then utilised for dominance and exclusion by regulating where, when and how girls sat. Sitting is seen to be an important marker of ownership, both of people and places, as well as a group management tool within student social groups.