EVER since Gavin and Stacey ended in 2010 Ruth Jones and James Corden have secretly texted each other ideas for the show's much loved characters, even though, when asked if the BBC comedy would return, the creators insisted again and again that it wouldn't.
"I always used to lie in the press and say, 'No, we're not doing any more', because until we absolutely knew we had something, there was no point in telling anybody," reasons Bridgend-born Jones (53), also known for Sky One hit, Stella.
Then, earlier this year, it finally happened; the announcement that a Christmas special was coming our way.
She and Corden thought, "there's no way we could do a series", remarks Jones. Instead, what we have is a one-off episode (just over an hour long) in which the gang head to Barry Island for the festive period.
It's tricky not to give spoilers away, so all we'll say plot-wise is this: it won't disappoint. All your favourite characters are back, plus one or two new ones too...
To recap, the original series followed the long-distance relationship of Gavin, who lived at home in Essex with mum Pam (Alison Steadman), dad Mick (Larry Lamb), and Stacey (Joanna Page), from Barry Island, Wales, where she lived with her mum Gwen (Melanie Griffiths), with her uncle Bryn (Rob Brydon), across the road.
Not forgetting Gavin and Stacey's respective best friends Nessa (Jones) and Smithy (Corden) who, after a one-night stand in series one, became parents to baby Neil in series two.
The final episode saw Gavin and Stacey, who married at the end of series one, find out they were having a baby.
Meanwhile, Nessa decided – at the altar – to take Smithy's advice and not marry Dave Coaches. And in the final scene, we saw all four of them sat by the beach in Barry Island – though Smithy and Nessa's relationship status is unclear.
Why wait until now to revisit these characters?
"More than anything, we wanted to be sure that, if we did bring it back, it was good," Jones, who is married to writer/producer David Peet and has three step-children, responds.
"We don't know what the reaction is going to be yet, but we didn't want to risk people going, 'Oh, it's not like it was'."
The writing process was tricky, seeing as Buckinghamshire-born Corden (41) now lives in LA, where he hosts The Late Late Show with James Corden, a talk-show on CBS.
The duo, who met as stars of ITV comedy drama Fat Friends (which first aired in 2000) found some time in September 2018 to map out the story. Then it took another week, in February this year, to finalise the script.
"And it was a bit of a journey, I have to say," says Jones.
"There were some times during that week where we thought, 'Oh, this isn't happening, let's not do it'."
The biggest challenge, she notes, was deciding on the storyline for Gavin and Stacey.
"Those characters are the heart of this show; the only reason that all these characters have ever come together is because Gavin and Stacey met and they got married, and so all these people got together, and they're now in each others' lives.
"And we felt, early on in the writing of this, 'What is it about Gavin and Stacey? We haven't got something solid and chunky for them'."
But, she promises, they are "really, really chuffed" with the storyline they decided to go with.
It's quite a shock to see how different Jones is in real life to rock-chick Nessa, who's famed for her tattoos, gothic make-up, and to-the-point, blunt attitude.
The glamorous star is chatty and enthusiastic – just as you'd hope someone who's penned a series as warm and entertaining as Gavin and Stacey would be.
It's touching to hear her talk about her working relationship with Corden, who couldn't be at the press day in London because of work commitments across the pond.
"We can argue, don't get me wrong – we have a very brother/sisterly relationship. But our friendship, at the heart of it, is so strong," she says. "I'm so proud of our friendship, and I'm proud of the journey we've been on together."
Then there's how "liberating" she found it getting into character again (viewers, get ready to hear, 'Oh, what's occurin'?' again). I just absolutely adore Nessa, because when I'm playing her, I just feel brave and so at ease.
"Lots of people would come and watch us film in Barry, but sometimes you couldn't get up the road or we needed someone to be quiet.
"It was great; I was able to go out there, and rather than, as Ruth Jones, go, 'Would you mind ever so being quiet while we film this?' I was able to go out and go [in Nessa's voice], 'Oh! We're trying to film in there, now come on, have some respect'."
Of the new episodes, she adds excitedly: "We see how she's developed as a mother. And I think she's a really lovely mum, because she seems to retain that Nessa-ness, but has a great relationship with Neil the baby."
One character who will be missing is Doris, who was Gwen's neighbour in the original series, and was played by Margaret John (the Welsh actress died in February 2011, aged 84).
Discussing how they came up with the story for this episode, Jones notes: "We didn't want to sensationalise it and have something major happen.
"It was a big enough real story that Margaret John was no longer with us, and therefore we chose to include that she [Doris] had died.
"We didn't want to make it a big explosion happen in Trinity Street or anything like that; we wanted to keep it as real as possible, as true to the characters as possible. But, also, you have to have a narrative drive in there as well."
She explains that, when it comes to the script, "we're always having to walk a bit of a thin line between making it soap, making it drama, making it believable, making it comedy. It's a bit tricky to navigate that."
Whatever difficulties they came across, one thing's for sure, for long-time fans, this revival has been well worth the wait.
:: Gavin and Stacey will air on BBC One on Christmas Day.
