Rihanna, left, and Stella McCartney attend The Metropolitan Museum of Art's Costume Institute benefit gala celebrating "Charles James: Beyond Fashion" on Monday, May 5, 2014, in New York. (Photo by Evan Agostini/Invision/AP)

Pictured: Margot Robbie Mandatory Credit ?? Gilbert Flores/Broadimage 2014 Costume Institute Benefit celebrating the opening of Charles James: Beyond Fashion 5/5/14, New York, New York, United States of America Broadimage Newswire Los Angeles 1+ (310) 301-1027 New York 1+ (646) 827-9134 sales@broadimage.com http://www.broadimage.com

(R-L) Cara Delevigne, Rihanna, Stella McCartney, and Reese Witherspoon arrive at the Costume Institute Benefit at The Metropolitan Museum of Art May 5, 2014 in New York. AFP PHOTO/Timothy A. CLARY

Pictured: Lily Donaldson Mandatory Credit ?? Gilbert Flores/Broadimage 2014 Costume Institute Benefit celebrating the opening of Charles James: Beyond Fashion 5/5/14, New York, New York, United States of America Broadimage Newswire Los Angeles 1+ (310) 301-1027 New York 1+ (646) 827-9134 sales@broadimage.com http://www.broadimage.com

Naomi Watts attends The Metropolitan Museum of Art's Costume Institute benefit gala celebrating "Charles James: Beyond Fashion" on Monday, May 5, 2014, in New York. (Photo by Charles Sykes/Invision/AP)

Cara Delevigne, and from left, Stella McCartney, Kate Bosworth and Reese Witherspoon attend The Metropolitan Museum of Art's Costume Institute benefit gala celebrating "Charles James: Beyond Fashion" on Monday, May 5, 2014, in New York. (Photo by Charles Sykes/Invision/AP)

05 May 2014 - New York, New York- Naomi Watts. "Charles James: Beyond Fashion" Costume Institute Gala. CAP/ADM/CS ??Christopher Smith/AdMedia/Capital Pictures

Hailee Steinfeld attends The Metropolitan Museum of Art's Costume Institute benefit gala celebrating "Charles James: Beyond Fashion" on Monday, May 5, 2014, in New York.

The Metropolitan Museum of Art 2014 Costume Institute Benefit Gala. Metropolitan Museum of Art, New York City, NY. May 5, 2014. Job: 140505A1. (Photo by Axelle Woussen/Bauer-Griffin) Pictured: David Burtka and Neil Patrick Harris.

The Metropolitan Museum of Art 2014 Costume Institute Benefit Gala. Metropolitan Museum of Art, New York City, NY. May 5, 2014. Job: 140505A1. (Photo by Axelle Woussen/Bauer-Griffin) Pictured: Hailee Steinfeld.

Sarah Jessica Parker arrives at the Costume Institute Benefit at The Metropolitan Museum of Art May 5, 2014 in New York. AFP PHOTO/Timothy A. CLARY

Sarah Jessica Parker attends The Metropolitan Museum of Art's Costume Institute benefit gala celebrating "Charles James: Beyond Fashion" on Monday, May 5, 2014, in New York. (Photo by Evan Agostini/Invision/AP)

Sarah Jessica Parker attends The Metropolitan Museum of Art's Costume Institute benefit gala celebrating "Charles James: Beyond Fashion" on Monday, May 5, 2014, in New York. (Photo by Evan Agostini/Invision/AP)

Hailee Steinfeld attends The Metropolitan Museum of Art's Costume Institute benefit gala celebrating "Charles James: Beyond Fashion" on Monday, May 5, 2014, in New York. (Photo by Evan Agostini/Invision/AP)

Charlize Theron and Sean Penn attendsThe Metropolitan Museum of Art's Costume Institute benefit gala celebrating "Charles James: Beyond Fashion" on Monday, May 5, 2014, in New York. (Photo by Charles Sykes/Invision/AP), APTOPIX