Love Thy Brother's Sister - S1.E9

Jeff hasn't dated since his divorce two years ago, but all that changes when Larry's sister Lori comes to town. They start a heated, secret affair behind Larry's back, knowing that he'd explode with rage if he found out. One day, Larry catches them fooling around, but instead of getting angry, he's thrilled. He assumes Jeff and his sister are going to get married. As the thrill of their secret romance fades, Jeff and Lori have to find a way to break the bad news to Larry without breaking his heart.