Interpersonal transgressions threaten victims, offenders, and their relationships, often leading the parties to ruminate about the wrongdoing, not only individually but also together, in acts of co-rumination. We investigate how two forms of co-ruminationco-reflection and co-brooding-influence, or are influenced by, individual rumination and victim forgiveness or offender self-forgiveness. Our study used a prospectivelongitudinal-dyadic design (N = 110 dyads), where relationship couples were recruited prior to an incident and, once a partner reported feeling wronged by the other, completed repeated surveys over four time-points 24-48 h apart. Cross-lagged panel models indicated that co-rumination was related to increased subsequent individual rumination; forgiveness and self-forgiveness were related to reduced subsequent corumination; and self-punitiveness showed positive feedback cycles with co-brooding and offender rumination, whereas genuine self-forgiveness seemed to draw on coreflection via individual rumination and, in turn, reduced co-reflection. Co-rumination plays an important, yet complex, role within processes of moral repair.