Sienna Miller in a bikini

By: The Superficial / August 14, 2009

Here’s Sienna Miller (G.I. Joe: The Rise of Cobra) in Ibiza yesterday most likely celebrating the fact she was actually in a movie people wanted to see for once. Well, at least for the first weekend until word gets out Channing Tatum has the screen presence of mayonnaise.

Photos: Splash News