Despite her success as both an actress and scriptwriter, Ruth Jones is decidedly unstarry, softly spoken and looks much younger than her 51 years.
Best known as Stella in the eponymous comedy series and as Nessa Jenkins in the hit comedy Gavin & Stacey, which she wrote with co-star James Corden, Jones is warm and funny, chatting happily about her life in Cardiff with her producer husband David Peet.
Her Edinburgh-set debut novel, Never Greener, features a young woman who has an intense affair with a married man, which ends in heartbreak. Fast forward 17 years and their lives have moved on. She is now a successful actress, married with one child; he is a teacher still married to the same woman, with three children.
Chaos ensues when the actress bumps into him again and the spark re-ignites. Jones sets the scenes in different timelines, rather like David Nicholls did in his hit novel One Day, building up the sexual tension between the lovers.
So, a fair amount of the book centres on lust and whether its power is greater than true love.
“Is it beautiful sex? No, it’s not. It’s very hedonistic and ego driven. What’s interesting is that it means something different to both of them,” Jones says.
The book first emerged from a screenplay she wrote in 2002 – which never made it to the screen – when people were getting in touch with friends from the past through the website Friends Reunited.
“You heard all sorts of stories about people leaving their long-term marriages to set up with people that they were going out with when they were 17. And a lot of those second attempts went wrong.”
But it wasn’t based on her own life, she insists, laughing.
“Of course I’ve been in love and I married the man that I love. It was love at first voice because I spoke to him on the phone before I met him. I did fall in love with his voice. But I have had to imagine a lot of the intensity and the destructiveness.”
Growing up in Porthcawl, Jones kept a diary as a 13-year-old and another in her 20s which, she says, shows how your personality changes as you get older.
“When I re-read my diaries, it’s the self-doubt that seems to be prevalent,” she reveals. “Since I turned 40, I’ve become less self-doubting, but it still happens.”
Because of this, she isn’t on social media – either Twitter or Facebook.
“I couldn’t handle it if somebody said something nasty,” she says. “But I have read comments that people have received. James [Corden], for instance, gets horrible comments from people. I’ve seen the stuff that’s been said and I just couldn’t handle it if people were being abusive.
“The world is crap enough without adding to that vitriol. People say it’s just like the modern day graffiti on toilet walls in the pub, or when you’re in a car and have road rage.”
Her novel attracted a bidding war, handled through her old Warwick University pal, top literary agent Jonny Geller.
“I am nervous about how my debut novel will be received, because there’s always that feeling that somebody might say something negative. I say I won’t read the reviews, but I probably will. But just because somebody says something negative, I don’t have to believe it.”
Apart from a book tour, life will go on as usual in Cardiff with Peet, who she met while working on a comedy pilot in the early 1990s. She has three grown-up stepchildren from his first marriage. While she has never had children of her own, being a stepmother seemed to come quite naturally.
“You take things as they come. There wasn’t a moment when I thought, ‘I’ve become a stepmum now’. We were really lucky. Our three were just gorgeous human beings. We never had any difficulty with teenage angst, and now I’m looking forward to becoming a step-grandmother at some point.”
The couple set up a production company and co-created Stella – doing 58 episodes together – but she says there won’t be any more.
“It took over our lives. We’d storyline the next series in August when we were still filming the previous series, so there was never a break.
“We loved it and created some fantastic characters that we still laugh about, but we knew we’d have to move on. I always say, ‘Never say never’ but it’s very unlikely.”
She also says she wouldn’t reprise Gavin & Stacey, although she has extremely fond memories of it and remains friends with James Corden.
“We used to talk about maybe doing a special, but if you look at the logistics of it, James lives in America and I don’t know how long he’ll be out there for. He’s so busy. Even if we did write something, when would we film it?
“James and I still have little conversations about what Nessa’s doing or what’s happened to Neil the baby, who is now about 10! We come up with little things that the characters are doing.
“I saw him last Christmas and we were crying with laughter just remembering the process of writing – it was such an innocent time.
“James would drive down to my house in Cardiff which had a leaking roof. We’d sit in the lean-to with the heater on, or I’d go to his flat and we’d sit there with a Chinese takeaway in Beaconsfield.
“Looking back, we have such affection for that time – and maybe that’s what made the series what it was. We started writing it 13 years ago. Would we still have the same innocence to put into the characters? I don’t know.”
She’s under contract to write a second book and has several other projects on the go, but these days, she shies away from red carpet bashes and other celebrity events.
“Well, I live in Cardiff and we haven’t got many ‘paps’ in Cardiff, I’ve got to say,” she says.
And she’s keen to keep a balance between her professional and her private life.
“If I’m doing a charity event and I’m there because that will give the event interest, then fair enough. People should be able to have their selfies and autographs.
“But the other day, I was in the car and my husband was just getting in when this guy came out, looked at me and literally pushed my husband out of the way. He said, ‘Excuse me, are you that woman from Gavin & Stacey?’ and my husband was left standing there. I just went, ‘No, not me’. Sometimes people don’t realise they’re being rude.”
She wonders how her pal Corden deals with the extreme fame he has attracted.
“I don’t know how real celebrities deal with it. For James and Julia, his wife, if you’ve got three small children and you’re out and about, it must be tricky.”
Never Greener by Ruth Jones is out now, published by Bantam, priced £12.99.