Jennifer Aniston is set to write a tell-all book about her divorce from Brad Pitt and his relationship with Angelina Jolie, according to a new web rumor. Brad and Angelina have been plagued by reports that they began a sexually relationship while co-starring on the set of the hit action flick Mr. & Mrs. Smith for years; at the time, Brad was still married to Jennifer. Jen’s alleged book will serve up hot scoop about when Brad began his relationship with Oscar-winning “baby mama” Angeline Jolie and the real reason behind their divorce.