ET is first on the set of the new Kristen Bell Disney comedy 'You Again,' and co-stars Jamie Lee Curtis and Sigourney Weaver face the embarrassment of wearing the same dress to a rehearsal dinner! Of course, the matching-dress mishap is just a scene from the movie, in which Kristen plays a girl who is horrified to learn that her brother (Jimmy Wolk) is going to marry the girl (Odette Yustman) who made her life miserable in high school. Not content to endure the misery to come, Kristen sets out to expose Odette’s evil ways.  "Sigourney is such a perfect person to have as my nemesis," says Jamie Lee, who came from self-described non-"arts and letters," Southern California movie-star parents. "It's just a really funny juxtaposition between the two of us because she is so smart, cultured and funny. ... I feel tiny around her in every way, so it's perfect." Continue reading... (ETonline.com)