One source claims the 18-year-old was actually bullied for being there -- apparently not everyone thought she earned the right to walk the shows!
The insider spilled:
Well our day is made.
Sienna Miller was a tit bit nipply in London after leaving the Groucho Club with designer Matthew Williamson on Thursday night.
With the actress's well-documented hatred of bras, her sheer top, and London's notoriously cold weather, the poor nip never stood a chance in hell of going incognito!
And without even knowing it, that pokie is a hero — it momentarily distracted us from Sienna's mismatched baggy floral pants and snakeskin top.
[Image via WENN.]