Interpersonal relationships are a pervasive dimension of human behavior and decision making. Actors make choices based both on personal goals, and on goals derived from interpersonal relationships. We present a goal-based model of decision making that combines the motives of the actor with agendas adopted through relationships. A unifying feature of the model is the use of importance as a means of ranking both goals and relationships. We describe a computer simulation of the model in the domain of Congressional roll-call voting.