Demi Lovato, Britney Spears and L.A. Reid celebrate "The X Factor" finalists at the SLS Hotel; Marion Cotillard brings her style A-game in Dior to the Rust And Bone premiere at AFI Fest 2012; Selita Ebanks, Eva Marcille and Jamie Kennedy hit the 22nd Annual NAACP Theatre Awards—get caught up on Monday's top events in this edition of Last Night's Parties.