Soaps are full of unlikely couples, and they don’t come much odder than Emmerdale’s Paddy Kirk and Chastity Dingle.

Paddy the bumbling village vet, played by Dominic Brunt, won over the firebrand, played by Lucy Pargeter, in February, but viewers suspected it would only be a matter of time before the union crumbled.

This week, just when a fearful Paddy decided he trusted his girlfriend enough to leave her alone in the Dales, Chas drunkenly ended up in bed with her old flame Carl King. Paddy makes the heartbreaking discovery in an episode due to be aired on Thursday.

“It’s Paddy’s worst fears realised,” explains Dominic, with an endearing giggle. “He’s never truly believed that Chastity is completely in love with him. He’s not possessive, but he’s not got much of an ego and has a lot of self-doubt.”

When Carl breaks the news to Paddy, the vet is predictably devastated and more than a little furious. “He has a bit of a fight with Carl, but it’s a pathetic Paddy fight as he’s not a great fighter,” says Dominic.

“Then he goes to the pub and confronts Chas in front of everyone, and dumps all her stuff in plastic bags.”

It’s a storyline the 39-year-old has relished. While he speaks with affection for his character, he admits that Paddy is “a bit wet” and that it’s been fun to give him a bit of fire in his belly for once.

“It was great just going for it. It’s a different way of playing him, for him to be that angry. He’s always been quite principled, but he’s a bit of a mouse really,” says Dominic. “In this storyline, he tells everyone what he thinks, but he still does it in his own way. He’s still Paddy. He’s not that great at it and finds it embarrassing.”

Rather than flooring his love rival with a well-aimed punch, the Paddy way of reacting involves smashing up his surgery in a rage.

And the actor couldn’t have been more pleased to do it. “It was just so great! I’d pay money to do it,” he enthuses. “You know how they organise paintballing? I don’t know why someone doesn’t organise a room in the middle of London where you’d have ten minutes, and for 50 quid you could smash everything in the room, tellies and everything. It was just amazing.”

Whether there’s a future for Paddy and Chas, Dominic is unsure.

“She did say she was drunk and did it, but I’ve been really, really drunk and not slept with Carl!” he says, giggling again. “I honestly don’t know about the long term.”

While the storyline is in the hands of the writers, he’s certainly had fun playing out Paddy’s latest doomed relationship, and with 12 years in the soap to his name, there have been a fair few of those.

“Working with Lucy has just been amazing over the past year. She’s so brilliant at what she does. She comes into work with such enthusiasm and that’s infectious. I love working with people who want to work.

“She reminds me of Lisa Riley (who played Mandy Dingle). She’s got a great imagination. So I’d love to work with Lucy again, but you’ve got to go with what the story does.”

One relationship that does still have mileage is Paddy’s friendship with Woolpack chef Marlon Dingle, played by Mark Charnock.

At this year’s British Soap Awards, where Dominic had a solo nomination for Best Comedy Performance, the duo earned a nod in the category of Best On-Screen Partnership. The pair are good friends off screen as well as on.

Dominic, who joined Emmerdale in 1997, says: “We lived together for a while. Obviously we’ve all grown up now and live in different towns, but we do knock around together. He really makes me laugh. We’ve got a very good working relationship.”

In April, the co-stars indulged their shared passion for zombie movies by organising their second annual Leeds Zombie Festival.

“We really wanted to do a film festival for charity and picked zombies because we’re both really into them,” he says. Despite insisting he’s “not a nerd about it”, the merest mention of this year’s Channel 4 drama Dead Set, about zombies invading the Big Brother house, prompts a torrent of praise from Dominic.

“Absolutely amazing, that!” he says. “Charlie Brooker, who wrote it, hates Emmerdale, but I just think he’s amazing.

“Did you see Davina McCall as a zombie? I thought the whole thing was incredible. A real surprise.”

He and Mark hope to be able to show the unedited version at next year’s festival, depending on whether they can get hold of the rights.

“It takes forever to organise getting film rights for the day, and posters, graphics and websites. We always said if it stopped being fun we wouldn’t do it, but we didn’t realise it would take a year to do each one!”

The pair are no strangers to graft, however. Their on-screen chemistry, not to mention their lengthy time in the show, is testament to how hard they work.

“We always try and get in early and work out what we’re going to do with the scenes. If we just came in and said our lines we’d have gone five years ago,” says Dominic.

Born in Macclesfield, father-of-two Dominic was a sheet-metal worker before becoming an actor. Before Emmerdale, he appeared in dramas such as Soldier Soldier, Morse and Holding On.

In 2000, Dominic bought the house that spawned the Cottingley Fairies legend. The terraced house was the home of Elsie Wright who, along with her cousin Frances Griffiths, fooled the world with hoax photographs of fairies taken at Cottingley Beck.

The T&A reported that Dominic called the purchase “a dream” for him as the story of Elsie and Frances Griffiths’s faked 1917 photographs was something that had interested him for years.

Emmerdale is on ITV, Monday to Friday at 7pm.