So Pippa Middleton donned a slinky number to attend the unveiling of the handsome actor's new film Shadow Dancer.
The 28-year-old looked pretty in a a fitted black dress with a lacy upper section covering her shoulders.
She finished the look with a pair of towering strappy sandals and a black clutch bag with silver piping detail.
Her shiny raven locks tumbled over her shoulders in loose waves.
Others at the premiere included actress Rosamund Pike, and newsreader John Snow, who was spotted doing 'the Mobot' – Olympic champion Mo Farah's distinctive celebratory pose.
Shadow Dancer tells the story of an member of the IRA who helps MI5 in order to protect his family. It's set in Belfast in the Nineties.