This study examined teachers’ claims of entitlement in collaborative teaching sequences where the non-leading teacher enters into the domain of another teacher’s ongoing instructional business. The data involves video recordings of second-grade elementary Korean and American teachers co-teaching math and science lessons. The analysis reveals that directives were prevalent in teacher-teacher communication, and unilaterally involved the Korean teacher making corrective remarks of American teacher’s instructions or entering to take control of classroom management. The directives were also formulated as declarative interrogatives, proposals, and imperatives, which implied the Korean teacher’s high entitlement. Also when the Korean teacher’s directive was not met with immediate compliance, it escalated into a more demanding imperative. These findings reveal the differential institutional status and power balance between the two teachers and demonstrate the analytical gains of applying conversation analysis to co-teaching interactional data. Potential implications for teacher training are discussed in light of collegiality and complementary collaborative teaching.