S3, E18: Chuck offers to throw a wedding for a very pregnant Dorota (recurring guest star ZUZANNA SZADKOWSKI) who insists that she and Vanya (recurring guest star AARON SCHWARTZ) have a traditional wedding before her parents arrive from Poland and find their daughter pregnant and without a husband. Dorota asks Blair and Chuck to be part of the ceremony and walk her down the aisle. Serena tells Nate she is having breakfast with the Humphreys when in reality she is secretly meeting up with Carter Baizen (recurring guest star SEBASTIAN STAN). Plus, Rufus discovers that Lily has been lying to him about her whereabouts.