Robert Pattinson Celebrates BFF Tom Sturridge and Sienna Miller Birthdays in London

There is nothing like supporting your BFF, and that is just what Robert Pattinson did last night in London. 

Sienna Miller threw a pre-birthday bash for her Tom Sturridge in West London last night (December 05, 2013), which included guests Poppy Delevingne and fiancé, model James Cook. Tom doesn’t actually turn 28 until December 21 (her birthday is actually on the 28th as well), but who throws a party on someone’s actual birthday anymore?

While Sienna was dressed to the nines in a strapless white dress with black stockings, Rob and Tom went ultra causal. Is it that hard to put on a nice shirt and pair of pants guys?

There are more pics of Robert and his BFF in the gallery above!