Callie's free-spirited and sex-obsessed sister, Kate, wears out her welcome at Adam and Callie's place, so the couple sets her up with a part-time job at Adam's office. When Ethan saves Lisa's life at a swimming pool, Mike shows his gratitude by giving him his beloved college t-shirt. But when Ethan flaunts the garment, Mike stages a table-tennis challenge to settle the score for rightful ownership. Meanwhile, Kate and Adam's obnoxious boss, Kev, start hooking up, making the work environment even more uncomfortable for Adam.