Sneak Peek! Gossip Girl: G.G.

The much-anticipated 100th episode will open with a musical dream sequence featuring Serena (Blake Lively), Blair (Leighton Meester), and all the men in their lives (Penn Badgley, Chace Crawford, Ed Westwick, and Hugo Becker).
While Chuck wrestles with the reality that Blair is about to walk down the aisle with Prince Louis, the return of Georgina Sparks (guest star Michelle Trachtenberg) might make the royal affair a royal disaster. Kelly Rutherford and Matthew Settle also star.
Gossip Girl airs every Thursday at 8 p.m. on ETC.