blakestairs4_460.jpgGivanni Rufino/Warner Bros

Marilyn Monroe in the 1953 hit Gentlemen Prefer Blondes
marilynstairs_460.jpg20th Century Fox

Blake Lively steps into Marilyn Monroe's heels for the upcoming 100th episode of Gossip Girl.

The starlet, as her character Serena van der Woodson, dons a platinum wig, gloves, a pink dress and loads of jewels for a modern-day, primetime interpretation of Marilyn's Gentlemen Prefer Blondes.

Accordingly, the men of the hit series take on the role of "Marilyn's" male chorus of admirers -- including Ed Westwick, Penn Badgley, and Chace Crawford.

Leighton Meester, aka Blair Waldorf, isn't left out of the dream sequence -- she makes an appearance as Audrey Hepburn.

Check out a gallery of photos from the episode and watch it Monday on the CW!