The phrase "When Gavin Met Stacey" refers primarily to the British TV series "Gavin & Stacey" and also to a book titled "When Gavin Met Stacey and Everything in Between" by Ruth Jones and James Corden. The book tells the full story of the show's creation and its cultural impact. If asking about the storyline in the TV series, Gavin and Stacey meet early in the show, which follows their romantic relationship. If referring to the book, it provides detailed insight into how the show was developed and the journey of its creators. For specific details about the exact time or episode when Gavin met Stacey in the show, the meeting happens near the beginning of the series. For more about the show's history and creation, the book offers a comprehensive recount told by its creators James Corden and Ruth Jones.