After being phone buddies for months, Gavin Shipman and Stacey West finally arrange a rendezvous in Leicester Square with Stacey's best friend Nessa and Gav's pal Smithy coming along for support.
After a huge misunderstanding on the phone, Stacey thinks Gavin has finished with her. He drives to Wales to explain and ends up taking her home with him. Having never been further than Bridgend before, her trip to Essex is an eye-opening experience that ends with the biggest surprise of all.
After his initial angry reaction to Stacey's news, Uncle Bryn agrees to drive everyone to Essex to meet the Shipmans. Pam has laid on a cracking spread and the party goes with a bang, but then Gavin and Stacey make an announcement that throws all the bonhomie out the window.
The Shipmans and Smithy travel to Barry Island for the wedding preparations; Gavin must choose between the horse and carriage that Stacey wants or the Bentley that he wants; and Nessa thinks she might be pregnant.
Stacey's brother Jason arrives home early, much to Uncle Bryn's horror. Stacey has her hen night, and Gavin has two stag nights, the second of which reveals something about Stacey that could jeopardise the whole wedding.
The wedding day has finally arrived, but whether they will go through with it is another matter; Uncle Bryn might finally admit what happened on the fishing trip; Nessa is conflicted.
Mick becomes a minor celebrity for the night, Stacey and Gavin start house-hunting, and Nessa visits Stacey and shows the others a thing or two at the bowling alley
It's Gwen's birthday and Bryn has arranged a special treat, but things take a surprising turn when an uninvited guest turns up, and Stacey tells Gavin of her big decision
Gavin is in Essex without his wife and Stacey is in Barry without her husband, so while Smithy plans a boys' night out, Stacey goes to the bingo, but has living separate lives finally taken its toll on love's young dream?
Stacey interviews for a new job while ensuring that Gavin sticks to his recent promise, and Dave is not a happy bunny when Nessa tells him she is taking baby Neil to Essex to see his dad.
Pam and Mick are having second thoughts about the conservatory; Bryn is in his element as he awaits the arrival of his houseguests: all the Essex boys down for a big night out in Cardiff.
Pete and Dawn are ready for a fresh start and decide to renew their vows, although Pete's ring threatens to ruin the big day. Meanwhile, Gavin and Stacey receive some awful news.
Pam and Mick unexpectedly arrive in Barry, and everyone, including Smithy and Doris, decides to spend the sunny day on the beach. But there are two questions on everyone's mind: will Dave be there? And, is Gavin really OK?
