The Scandal star's daring Marc Jacobs gown showed off some leg with a thigh-high slit. The sultry look stood out at the star-studded fashion event at the Metropolitan Museum of Art in New York City
Washington paired the gown with long, sheer, black Marc Jacobs gloves and black, Gianvito Rossi heels. However, the best complement to the ensemble was her dark, purple new hair style.
It was the perfect pseudo-futuristic accent that made the outfit fit this year's Met Gala theme, "Manus x Machina: Fashion in an Age of Technology."
Washington wasn't the only star flaunting her growing figure on the red carpet. Emily Blunt and Olivia Wilde also showed off their sizeable baby bumps, and couldn't have looked better.
ET confirmed on Monday that Washington, 39, and her husband, Nnamdi Asomugha, are expecting their second child. The couple, who tied the knot in June 2013, welcomed their first child, daughter Isabelle Amarachi, in April 2014.
For more on Washington's big baby news, check out the video below.