Rachel Bilson and Karl Lagerfeld debuted their series of short films for Magnum ice cream last night at the Tribeca Film Festival in NYC, and she headed to Barbados with her boyfriend, Hayden Christensen, by her side this morning. Rachel, who dressed in Chanel couture for the premiere, stars as a model, art student, and ballerina in the trio of Lagerfeld-directed ads. Many famous fashion-world figures were on hand to lend their support to the project, including Vogue editor Anna Wintour. Rachel stopped to talk with Fab on the red carpet and said it was easy to choose her favorite character from the series. "Ballerina. You got to wear a professional ballerina costume and be up on stage. Just to pretend for a second — what those women do is so incredible, so it was a lot of fun." Rachel has been a longtime muse for Karl, as well as The O.C.'s creator Josh Schwartz, who cast her as the lead in his latest pilot Hart of Dixie. Rachel recently shot the first episode in North Carolina and told us her character is a hard-driving surgeon who is forced to relocate to a small town in a classic fish-out-of-water storyline. Stay tuned to PopSugar Rush today for even more from our interview with her!