Successful restaurateur and man-about-town Jimmy Martino (John Stamos) is used to being the most suave, most handsome and most single person in the room. But everything changes with the surprise appearance of Jimmy's adult son, Gerald (Josh Peck), and his baby daughter, Edie. Now Jimmy has to unlearn a lifetime of blissful selfishness and grapple with the fact that he went straight from single to grandfather in six seconds flat.