The study examined measurement models of parent-adolescent dyadic affective flexibility and identified ways that this relational flexibility meaningfully changed in the context of adolescent anxious and depressive symptoms, both concurrently and over time. Ninety-one mother-adolescent dyads completed two five-minute tasks. Observational data were coded in real-time and examined second-by-second. Flexibility metrics were calculated (i.e., range, transitions, average mean duration, dispersion). Results supported a two-factor model of flexibility and suggested that all four metrics contribute to the construct. Adolescent internalizing symptoms positively related to flexibility, both concurrently and across a 6-month time period. Thus, dyadic affective flexibility appears best measured by utilizing all four metrics, and individual characteristics (i.e., anxious/depressive symptoms) influence dynamic family processes.