Jennifer Aniston and Jon Hamm — whose latest on-screen sex scene has gone viral — have always wanted to work together. So when the “Morning Show” creators were looking to cast the role of newcomer Paul Marks, it was a done deal.“Who would play Paul was a list of one,” executive producer Kristin Hahn previously told The Hollywood Reporter. “Jen and Jon have been friendly for years and have wanted to work together I think for a while.”“So when Paul Marks became a part of the conversation, it was a list of one,” she continued.