Family Guy Season 6 episode8

Peter has developed an obsession with mustache. While trying to save a man from the burning McBurgertown, he burns his mustache to a cinder. The man Peter saved turns out to be the manager of McBurgertown; to show his appreciation, he offer Peter lifetime supply of burgers. At McBurgertown, While eating the 30th burger, Peter suffers a stroke. After being hostipalized, he is frustrated to learn that the left part of his body is paralyzed, and he blames McBurgertown for his misery. Three months later, Peter passes by a Stem Cell Research Lab; he limps in and five minutes later, walking out completely healed.
Peter and Brian disguise as investors and infiltrate McBurgertown's headquarter to find criminal evidence to damage its reputation.
They find a slaughterhouse in the building, and a talking cow, which is willing to testify against the company.
Brian wagers that Stewie can't become the most popular boy in highschool. But he is wrong, and not only does Stewie become the most popular boy, he also gets a date with Connie D'Amico, who breaks up with Stewie because of his "baby penis".