Cele|bitchy | Sienna Miller screws up her big fashion contract

Just like Jessica Simpson, Sienna Miller has been spotted out in the wrong brand of jeans when she’s contractually obligated to wear a certain brand:

This week, glossy magazines carried photos of Miller shopping in a pair of jeans from a designer called LoFli.

So far so uncontroversial. But my man in the rag trade points out that la Miller signed an exclusive deal in November to be the “face and body” of Pepe jeans.

“Not only did Sienna do a racy photo-shoot on a beach in Malibu, she also agreed in writing not to wear rival products,” I’m told. “Not surprisingly, Pepe now want her to explain what’s going on.”

Yesterday, the jeans firm’s spokesman insisted: “Sienna is contracted only to wear Pepe jeans, so we’re sure it must be an old photograph.”

Oops. Guess a fashion contract means that you can’t even go out of your house wearing clothes that aren’t sponsor-approved. It’s not as big a sponsor faux pas as Jessica Simpson made, though. According to a new lawsuit against her, she named “True Religion” as her favorite brand of jeans when she was supposed to promote a line named after her creepy father’s nickname for her, “Princy.”

Here is Miller on the set of “Interview,” in which she plays a soap actress who gets interviewed by a “fading political journalist” played by Steve Buscemi. Hillary Duff is shown in the same dress as a host of the 2005 Teen Choice Awards. Via ONTD!.