After the stunning red carpet , many of the fashionable stars of the Costume Institute Gala  headed over to an afterparty hosted by Marc Jacobs  at the Monkey Bar in NYC last night. Jessica Biel  and Justin Timberlake  changed out of their formal wear into something more playful to party the night away. Kate Hudson , Liv Tyler , Kate Bosworth , Agyness Deyn and Stella McCartney  all crammed into the backseat of a car, staying together after walking the red carpet . It was hard to miss Madonna  in her eye-catching outfit  as she went home on the arm of Jesus Luz . Josh Hartnett  joined in on the festivities looking dashing in his tux, and even Naomi Campbell  came out to play despite boycotting the gala . Don't forget to check out all of Fab  and Bella's  coverage today of the glitzy event.
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To see more photos including Claire Danes , Selma Blair , Rihanna  and many others just .
Images include: Justin Timberlake, Madonna, Kate Hudson, Jessica Biel, Stella McCartney, Rihanna, Agyness Deyn, Jesus Luz, Liv Tyler, Kate Bosworth, Naomi Campbell, Josh Hartnett, Claire Danes, Hugh Dancy, Bruce Willis , Emmy Rossum, Eva Mendes , Anne Hathaway , Blake Lively , Penn Badgley , Selma Blair, Katy Perry , Miranda Kerr , Bar Refaeli , Kirsten Dunst , Billy Joel, Katie Lee Joel