My Giving-everything Sister-in-law

A man who still can’t get over his ex-girlfriend after several years. One day, his older stepbrother says he’s going to introduce the woman he’s marrying, and brings her home. It’s none other than that very ex-girlfriend. The man still hasn’t forgotten her, but now that she’s about to become his sister-in-law, he resolves to let her go completely and move on. A few months after his stepbrother and the ex-girlfriend get married, the man discovers something he never knew: because of his stepbrother’s perverse sexual fetishes, his sister-in-law is into twisted, deviant sex every single night. Unable to bear seeing the woman he once loved suffer like this, the man decides to steal his sister-in-law away from his stepbrother.