Spotted: Mila Kunis and Justin Timberlake having a laugh in N.Y.C. on the set of their new film, Friends With Benefits. The adorable duo are just two members of the star-studded cast, which also includes Natalie Portman, Emma Stone, Ashton Kutcher and Yankees third baseman Alex Rodriguez. Kunis looked perfectly chic in a tiny floral-print tee, black skinny jeans and killer heels, while Timberlake was as handsome as ever in a classic striped tie and khakis. The film shows the couple attempting to take their friendship to the next level, but it seems Kunis isn't Timberlake's only love interest: A mysterious leggy blond looks like she's also vying for his heart. Friends With Benefits is slated to hit theaters in January 2011. Click through our gallery to see more behind-the-scenes photos now.