According to Red Sox super-fan Ben Wrightman, finding romance is about as likely as his beloved team winning the World Series. But when Ben scores a beautiful new girlfriend, suddenly anything is possible.

Will is a good-looking, smooth-talking bachelor whose primary goal in life is to avoid any kind of responsibility. So he decides to invent an imaginary son in order to meet attractive single moms. Will gets a lesson about life from a bright but hopelessly geeky 12-year-old named Marcus. Now, as Will struggles to teach Marcus the art of being cool, Marcus teaches Will that you are never too cool to grow up.