S3, E21: When things get tense between Rufus and Will (recurring guest star WILLIAM "BILLY" BALDWIN), Serena chooses to stand behind her father, while Rufus is made to feel like an outsider within his own family. Meanwhile, Jenny deliberately shares information with Will that may ultimately destroy Lily and Rufus' marriage. And, after many failed attempts, Chuck makes one last grand gesture to reconcile with Blair, hoping she will finally accept the fact that they are destined to be together.