Partners in close relationships relate to each other emotionally in rich and diverse ways. First, people may be objects of each other’s emotions such as when one spouse’s anger elicits the other’s anger (emotional contagion), or when a therapist feels the client’s sadness (empathy). Second, understanding each other’s emotions facilitates partners’ coordination in daily life, leading either partner to approach, back off, express concern, or make other adjustments based on the other’s emotional state (emotional responsiveness). They may also modify their own emotions (emotion regulation) in response to each other and pursue emotional goals together such as overcoming the emotional damage of a transgression (emotional co-regulation). Third, emotions serve as guardians of relationships such as when love indicates connection, or hurt and jealousy signal threats. Fourth, social roles are enacted through emotions such as anger, shame and gratitude. Fifth, relationships can be characterized broadly in emotional terms such as positive/negative, regulated/unregulated, or emotionally expressive/inexpressive. Finally, partners influence each other’s reactions to their environments such as when they exchange opinions or share experiences (social referencing and emotional convergence). All these emotional processes may serve the well-being of the partners, the relationship, or extra-relational goals.