Diane Kruger is tired of looking like every other actress on the red carpet.
She's sick of tight dresses and slim fit suits! She's over fabrics that don't breath and silhouettes that hide her figure! So if The Host actress wants to wear silk pajama pants and a cropped workout top to a dinner party, that's what she's going to do!
Nevermind that those are very fancy Prabal Gurung lily-printed tuxedo pants. Diane will wear them as she pleases (i.e. with a midriff baring tank top). Rules are meant to be broken!
Note: Do not attempt this look if you are not a famous actress with an insanely killer body. Actually, on second thought, do not attempt this look if you are not Diane Kruger.