When Blair's (Leighton Meester) father, Harold (guest star John Shea), comes home for the holidays with an unexpected guest -- his boyfriend, Roman (guest star William Abadie) -- Blair finds it difficult to hide her disappointment and hatches a plan to get rid of Roman for good.
Jenny (Taylor Momsen) and Vanessa (Jessica Szohr) help Serena (Blake Lively) plan the best Christmas surprise ever for Dan (Penn Badgley), who may have a surprise of his own in mind for Serena. Chuck (Ed Westwick) texts Blair that Nate (Chace Crawford) has joined him in Monaco, worrying Blair that Chuck may disclose the details of their hook-up.
Rufus (Matthew Settle) refuses to remain the understanding husband any longer after Alison's (guest star Susan Misner) former lover calls the house. Kelly Rutherford also stars.