The experiences of Irish sons and daughters born into heterosexually-organised parental partnerships/unions whose parents have separated and one has come out as Lesbian, Gay or Bisexual (LGB) were explored through a grounded theory approach. 15 adult children (over the age of 18 years), who varied in age when their parents separated and one disclosed as LGB, were interviewed. The primary concern that emerged centred on participants having to adjust to their parents' being separated, as opposed to their parent being LGB. This involved engaging with the tension that arose from the loss of the parental union, which involved changes to the home environment and adapting to new parental partners and family units. Heightened reflection on sexual orientation and an increased sensitivity to societal LGB prejudice were specifically associated with a parent coming out as LGB. How parents negotiated disclosing the changes to others, the level of support available to parents, and how capable parents were at maintaining the parent-child relationship had an impact on the tension experienced by sons and daughters. Participants moved from initially avoiding and resisting the family changes that were occurring to gradual consonance with their altered family environments. Concluding directions for research and clinical considerations are suggested.