14/08/2014 12:32 BST | Updated 22/05/2015 06:12 BST

Fashion's BFFs: Sienna Miller &Amp; Matthew Williamson's Night On The Town

The Groucho club is a favourite celebrity haunt - ALL the cool cliques hang out there. So seeing the likes of Sienna Miller and Matthew Williamson leaving there together arm-in-arm this week was pretty standard. That said, we LOVE this dinner date duo. Date night with your fashion BFF is definitely a thing.


Sienna went for a mismatchy ensemble; a black and white (backless) print top tucked into silk floral print trousers with espadrille wedges and a black clutch. Proof that she's got an eye when it comes to fashion AND a designer friend on hand.

After revealing that she's taking a bit of time out from acting this month - Sienna's focus is all on her daughter Marlowe. And backing her actor fiance Tom Sturridge too, obvs.

The lady knows style and is guaranteed to be FROWing during London Fashion Week come September - especially at Williamson's show. Until then, take a click through this gallery to steal Sienna's style...