Mistresses 4×12 “Back to the Start” – April wrestles with how to tell Marc she’s pregnant, while he gets great news about his career. Karen and Adam’s relationship moves to the next level when she meets his parents. Meanwhile, the Lydia situation rears its ugly head one last time for Karen, with devastating consequences. Kate’s anger at Joss is as hot as ever, until she finds out the real truth of what happened with Scott. Based on the hit U.K. television series of the same name, Mistresses airs Monday, September 5th on ABC.