The butt belongs to Beautiful Creatures star Emmy Rossum, getting ready backstage for an interview with Conan.

The 26-year-old actress looked old-Hollywood glam in a polka-dotted dress and red pumps.

On the show, Emmy sang for a pastrami sandwich and promoted her upcoming movie.

Before she hit the stage, she Tweeted: “Very excited to go hang out with my buddy @ConanOBrien tonight. He’s my favorite ginger.”

Emmy’s new album, Sentimental Journey, hits the stores today!