Gossip Girl III (19)

When Lily's ex-husband Dr. William van der Woodsen (recurring guest star WILLIAM "BILLY" BALDWIN -- Dirty Sexy Money, Backdraft), shows up unexpectedly in Manhattan, Serena finally gets the reunion with her father she has so desperately wanted -- but the circumstances turn out to be far from ideal. Meanwhile, Serena and Nate continue to have relationship issues, and a scheming Jenny is more than happy to be a shoulder for Nate to lean on. Plus, Dan finds out that he didn't get accepted into the Tisch writing program and Vanessa admits she may have been somewhat responsible.