LW2 better be prepared for some unwelcome results if they do go the Ancestry/23andMe route. One of my cousins did one of those and found out she had a previously unknown older half-sister that way -- talk about awkward. If Gil's suspicions that he is not the biological son of his parents (son of an affair, son of the older brother for some reason, straight-out adopted) are true, you'd need to be ready to deal with that.