A source tells Hollywoodlife.com, ''She and JR are good friends. They always have been. She’s on good terms with all her ex’s but that doesn’t mean she’s dating them. They were both out chilling and celebrating last night – just having a good time.''NOW magazine claims Chris Brown may write a tell-all book. A source says, ''Chris knows better than anyone the sordid details of Rihanna's hard-partying lifestyle, from her drug use to her saucy antics and, of course, her different relationships.''