S2, E5: A furious Blair learns in the midst of Fashion Week that her mother, Eleanor (recurring guest star MARGARET COLIN), at the suggestion of her protégé Jenny, has given Serena and her new socialite friend, Poppy Lifton (guest star TAMARA FELDMAN - "Dirty Sexy Money," "Supernatural"), front row seats to the Eleanor Waldorf show. Hurt once again by Serena's popularity and her mother's betrayal, Blair decides to sabotage the show. Meanwhile, Dan starts hanging out with Chuck, and learns the hard way that a walk on the dark side always has its risks. Plus, Lily learns a secret that her new husband, Bart (recurring guest start ROBERT JOHN BURKE), has been keeping from her. Designer MICHAEL KORS and socialites TINSLEY MORTIMER and CRISTINA CUOMO make cameo appearances at Eleanor Waldorf's show.