Blake Lively as Serena Van Der Woodsen in the Season 5 episode "Con Heir."The CW/Giovanni Rufino - Wednesday, April, 4, 2012, 5:4 PM

Kaylee DeFer as Charlotte 'Charlie' Rhodes in the Season 5 episode "Con Heir."The CW/Giovanni Rufino - Wednesday, April, 4, 2012, 5:4 PM

Kelly Rutherford as Lily Van Der Woodsen in the Season 5 episode "Con Heir."The CW/Giovanni Rufino - Wednesday, April, 4, 2012, 5:4 PM

Wallace Shawn as Cyrus Rose, Leighton Meester as Blair Waldorf and John Shea as Harold Waldorf in the Season 5 episode "G.G."The CW/Giovanni Rufino - Monday, January, 30, 2012, 9:30 PM

Nan Zhang as Kati, Amanda Setton as Penelope, Blake Lively as Serena Van Der Woodsen and Hugo Becker as Louis in the Season 5 episode "G.G."The CW/Giovanni Rufino - Monday, January, 30, 2012, 9:30 PM

After five seasons filled with plenty of fierce fashion, decadent parties, and delicious scandal, "Gossip Girl" reaches its 100th episode on January 30. Fans of the show know that Blair Waldorf (Leighton Meester) often escapes reality by reveling in Audrey Hepburn fantasies, but for the show's milestone occasion Serena van der Woodsen (Blake Lively') will be indulging in a dream sequence of her own. In the episode, Serena channels the iconic Marilyn Monroe in a pink dress, elbow-length gloves, and heaps of diamonds à la "Diamonds Are a Girl's Best Friend" from "Gentlemen Prefer Blondes." Along with Blair dressed as Audrey, the dapper dudes of the Upper East Side will be joining Serena for the musical number in fancy suits and sashes. According to executive producer Josh Safran this Marilyn number has been something he's wanted to film since the show's first season. "It's something we've never done before. From Season 1, I said, 'I want to do this.' But it just wasn't the right time. I've been pushing it for five years, and it finally happened." Click through to check out more photos from the scene.The CW/Giovanni Rufino - Wednesday, January, 25, 2012, 8:25 PM

Chace Crawford as Nate Archibald, Ed Westwick as Chuck Bass, Blake Lively as Serena van der Woodsen, and Penn Badgley as Dan Humphrey in a dream sequence from the 100th episode of "Gossip Girl."The CW/Giovanni Rufino - Wednesday, January, 25, 2012, 8:25 PM

Hugo Becker as Louis, Penn Badgley as Dan Humphrey, Ed Westwick as Chuck Bass, Chace Crawford as Nate Archibald, Leighton Meester as Blair Waldorf, and Blake Lively as Serena van der Woodsen in a dream sequence from the 100th episode of "Gossip Girl."The CW/Giovanni Rufino - Wednesday, January, 25, 2012, 8:25 PM

Leighton Meester as Blair Waldorf, Penn Badgley as Dan Humphrey, and Blake Lively as Serena van der Woodsen in a dream sequence from the 100th episode of "Gossip Girl."The CW/Giovanni Rufino - Wednesday, January, 25, 2012, 8:25 PM

Ed Westwick as Chuck Bass, Chace Crawford as Nate Archibald, Blake Lively as Serena van der Woodsen, Hugo Becker as Louis, and Penn Badgley as Dan Humphrey in a dream sequence from the 100th episode of "Gossip Girl."The CW/Giovanni Rufino - Wednesday, January, 25, 2012, 8:25 PM

Blake Lively as Serena Van Der Woodsen in the Season 5 episode "The End Of The Affair."The CW/Giovanni Rufino - Wednesday, January, 25, 2012, 8:25 PM

Leighton Meester as Blair Waldorf in the Season 5 episode "The End Of The Affair."The CW/Giovanni Rufino - Wednesday, January, 25, 2012, 8:25 PM

Leighton Meester as Blair Waldorf in the Season 5 episode "The End Of The Affair."The CW/Giovanni Rufino - Wednesday, January, 25, 2012, 8:25 PM

Elizabeth Hurley as Diana Payne, Blake Lively as Serena Van Der Woodsen, and Brian J. Smith as Max in the Season 5 episode "The Big Sleep No More."The CW/Giovanni Rufino - Tuesday, November, 15, 2011, 7:15 PM

Elizabeth Hurley as Diana Payne and Kaylee DeFer as Charlotte 'Charlie' Rhodes in the Season 5 episode "The Big Sleep No More."The CW/Giovanni Rufino - Tuesday, November, 15, 2011, 7:15 PM

Elizabeth Hurley as Diana Payne in the Season 5 episode "The Big Sleep No More."The CW/Giovanni Rufino - Tuesday, November, 15, 2011, 7:15 PM

Elizabeth Hurley as Diana Payne in the Season 5 episode "I Am Number Nine."The CW/Giovanni Rufino - Wednesday, November, 9, 2011, 1:9 AM

Leighton Meester as Blair Waldorf in the Season 5 episode "I Am Number Nine."The CW/Giovanni Rufino - Wednesday, November, 9, 2011, 1:9 AM

Kaylee DeFer as Charlie Rhodes and Chace Crawford as Nate Archibald in the Season 5 episode "I Am Number Nine."The CW/Giovanni Rufino - Wednesday, November, 9, 2011, 1:9 AM

Roxane Mesquida as Beatrice Grimaldi and Joanne Whalley as Princess Sophie Grimaldi in the Season 5 episode "The Fasting and the Furious."The CW/Giovanni Rufino - Tuesday, October, 25, 2011, 8:25 PM

Hugo Becker as Prince Louis Grimaldi and Leighton Meester as Blair Waldorf in the Season 5 episode "The Fasting and the Furious."The CW/Giovanni Rufino - Tuesday, October, 25, 2011, 8:25 PM

Ed Westwick as Chuck Bass in the Season 5 episode "The Fasting and the Furious."The CW/Giovanni Rufino - Tuesday, October, 25, 2011, 8:25 PM

Kaylee DeFer as Charlie Rhodes in the Season 5 episode "The Fasting and the Furious."The CW/Giovanni Rufino - Tuesday, October, 25, 2011, 8:25 PM

Elizabeth Hurley as Diana Payne in the Season 5 episode "The Fasting and the Furious."The CW/Giovanni Rufino - Tuesday, October, 25, 2011, 8:25 PM