This study examined young adult grandchildren's self-reports about the influence of grandparent sex on perceived grandparent painful self-disclosure (PSD) as well as their reactions to grandparent dyad PSD. Perceived grandmother and grandfather motivations for "overall" communication were assessed as mediators of young adult grandchildren's discomfort with grandparent dyad PSD. Findings show that participants perceived PSD more in their interactions with their maternal grandmothers compared to their maternal grandfathers. These young adult grandchildren were less likely to report discomfort if they perceived grandparents to be communicating overall for the purposes of positive affect, or identity, but more likely to feel discomfort if they perceived grandparents to be communicating for the purpose of control. (Contains 3 tables, 2 footnotes and 2 figures.)