Business in the front, party on the side? Rebecca Hall took the sideboob baring trend to a whole new level at the premiere of Iron Man 3 in London on Thursday, April 18.

The 30-year-old actress flaunted major sideboob by going braless in a black Lanvin jumpsuit with cut-out sides to the screening at Odeon Leicester Square. The British star completed the sexy look by wearing bright red lipstick and pulling her hair back in a small bun.

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Hall, who confirmed in November 2011 that she was dating Kate Winslet's ex-husband Sam Mendes, posed on the red carpet with costars Robert Downey Jr. and Sir Ben Kingsley. The Town actress took over the role of sexy scientist Maya Hansen in Iron Man 3 cast after Jessica Chastain dropped out in May 2012. 

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"Sorry to say that Iron Man 3 isn't going to work out. My schedule is jam-packed and I can't fit anything else in. The press announced my possible attachment far too soon," the Oscar-nominated actress explained of her departure at the time. "I'm very excited to see the film when it comes out."

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This article originally appeared on Rebecca Hall Flashes Major Sideboob at Iron Man 3 Premiere in London