MARY arrives first and takes her usual place on the right of the screen. Her face is close to the camera – close enough for me to see her eyes narrowing slightly when Giles steps out of line. If you watch Gogglebox, you’ll know that this is how their relationship seems to work – Giles being annoying and Mary being annoyed – but give or take a few bumps, their marriage seems to work pretty well. In fact, they’ve got a few tips to pass on. How to Get Through Marriage And Still Like Each Other (Most of the Time), by Giles and Mary.

Giles, just like he does on Gogglebox, is sitting to the left of, and a little above, Mary, although when I first contact the couple via FaceTime, he is nowhere to be seen. A family friend has to be despatched to find him and after a few minutes, he appears at the back of the room and ambles across from the door. The couple are in one of the bedrooms in their Wiltshire cottage rather than the famous room with flowery wallpaper and matching chair, but the interior decor is much the same. The cottage is like their opinions: busy, a little old-fashioned maybe, but colourful and bright.

One of the subjects exercising them at the moment, they tell me, is the state of masculinity. Giles says both he and Mary are fans of Jordan Peterson the American psychologist whose views on men, gender and individual responsibility have been winding up feminists and liberals for a while now. Giles in particular thinks this is great fun because saying you like Jordan Peterson has the potential to be annoying and Giles like to be annoying. He says it was the only way he could get attention from his parents when he was a child, so some 50 years later he’s still doing it.

What particularly drew the couple to Jordan Peterson, says Giles, was the psychologist’s book 12 Rules For Life, in which he criticises the “yes you can” attitude common on the X Factor-style shows that Giles and Mary have to watch on Gogglebox. The positive but unrealistic platitudes of reality TV are one of the things that Giles and Mary hate (Giles says their family motto is “there’s no such word as can”); they also hate hugging, flowers in cellophane at accident blackspots, and cliches on fridge magnets. Giles and Mary are mostly united by what they disapprove of.

One of the good things about Peterson’s book, says Giles, was finding support for their views on happiness. “We’re big fans and watch him on YouTube and one of his things is that the quest for personal happiness is a pretty hopeless way of spending your life, which is what we’ve always said, especially about marriage,” says Giles. “We’ve got quite a robust approach to personal happiness and it turns out that he says exactly the same thing. It’s a very good book. Young people are flocking to him because they’re living in a world where there’s practically no judgment about rules or regulations and discipline and they are really quite lost, a lot of young men especially. This idea of a sense of entitlement. There’s a crisis in masculinity and Jordan Peterson has been tackling it head on.”

Mary has been nodding along to all of this. “Young men have never been so attacked,” she says. “They’re accused of being sexist patriarchs. Older men also have never had such a hard time. I think the time comes when there are very few people you can attack because everyone is off limits – so currently we attack the upper classes and men.”

Mary does have a confession though: she has been part of the problem. If you watch Gogglebox, in which British families watch a selection of the week’s telly, you’ll have noticed Mary sighing and telling Giles off; for some years, she also made fun of her husband in newspaper columns (Mary is a journalist in her full-time job) and now she’s feeling a bit guilty. “I, and other women, have gone too far,” she says.

Mary is particularly thinking of Twitter when she says this, as well as other forms of social media where the default setting seems to be “attack”. Mary tells me that she’s just arranged to have their Twitter password changed on the computer so Giles can’t go on it and read out the comments to her. There was one the other day apparently about Mary wanting to bludgeon Giles to death with an axe, which Mary found upsetting so she prefers to avoid the site.

In fact, type the words Giles and Mary into Twitter and, give or take a few nasty words, the vast majority of comments are positive – loving even. Giles and Mary have been on Gogglebox since the fifth series in 2015 (famously calling each other Nutty for a reason neither of them can remember) and they have become one of the show’s most popular families. They are not “break-out stars”, says Giles, but they have written a Charles Pooter-style book about their lives, The Diary Of Two Nobodies and next weekend they will be appearing at the Boswell Book Festival near Cumnock in Ayrshire. In their own eccentric way, they have become symbols of British domestic life.

One possible reason they are so popular is that the way they act is the way a lot of long-term couples act. Giles Wood, who comes from a part-Scottish family (his grandmother was from Aberdeen) and Mary Killen (who grew up in Northern Ireland) have been married for more than 30 years and have two grown-up daughters, so it’s only natural that they get on each other’s nerves sometimes. In some ways, they are also very different kinds of people. Mary is gregarious; Giles is introverted. Mary derives energy from other people; Giles, he tells me, is like a leaky battery and needs to go and lie down after a bout of energy-draining socialising. Sometimes, says Giles, marriage to Mary feels like Brexit and Remain.

However, over the years, the couple have found ways to deal with their differences, some more unusual than others. Mary says there was a time when they would use an oven timer to give each other five minutes to talk without the other interrupting; Mary has also been known to record their disagreements on her phone so they can play them back and both realise where they went wrong.

However, one thing has helped their marriage more than any other and that’s Gogglebox, even though at first Mary was resistant to taking part.

“I just didn’t watch television,” she says, “because I only really liked daytime telly. I think the trouble was I used to work so hard that when I stopped working at 8 o’clock I threw back three glasses of wine before Giles, who’s brilliant at cooking, served supper at 9; I’d choke it down and then fall asleep.” The couple were also unashamedly middle-class and snobby about television – Giles in particular was brought up to believe that you should be doing something else instead, like reading a book or playing outdoors. But being part of Gogglebox has changed all of that. For a start, the couple have discovered that they quite like low-brow culture – dramas like Doctor Foster and reality shows like Bear Grylls – but taking part in the show has also reminded them what they have in common and brought them closer.

“The fact is that while we’re being filmed for Gogglebox, we’re chatting a lot in between,” says Mary. “This enforced chatting and sitting next to each other while they’re fixing the lighting or something means we get to cover a lot of ground. In the past what used to happen is that I’d get up at six and work until eight with hardly a lunch break and he’d get up at 11 and we didn’t actually overlap that much. Now we are overlapping. We rubbed along because we didn’t see each other but now we’re rubbing along better because there’s a bit of chat.”

Giles would even go so far as to say that Gogglebox has saved their marriage. The programme means they are no longer intimate strangers, he says, and they have rediscovered the fact that they have a similar sense of humour and like the same people. “There’s also an element with us,” says Giles, “that if we’ve reached this stage of not divorcing – and many of our contemporaries have – it’s like a club where we started to club together with the other non-divorced. We’re looking around and thinking ‘god, we’re a real rarity’.”

The trickle of money from Gogglebox has also helped the domestic atmosphere. “I don’t get paid anything like Ant McPartlin,” says Giles, who used to make a small living as a painter, “but I now pay the council tax bill so I’m helping the balance of payments.”

Not everyone can be on Gogglebox of course, but both Giles and Mary think there are some lessons in their experiences for other couples, particularly young people starting out. “I’ll never forget when I was in labour,” says Mary, “and I was taught how to distract myself from the pains by just realising that they would be over eventually and that’s a really good analogy for marriage because it’s not all going to be plain sailing. When you know the goal at the end, it’s worth distracting yourself from the painful periods.” “And the children would prefer us to be together,” adds Giles. “They sometimes say ‘thank God you’re not divorced’.”

Mary also has a curious theory about the connection between television and relationships. She and Giles grew up, she says, before the widespread advent of videotapes and DVDs which meant that when you sat down to watch the telly, you either stuck with it or lost it forever, and Mary thinks there’s a lesson to be learned there for relationships: don’t be in a rush to move on, don’t press “eject” before you’ve truly worked out whether or not you like what you’ve got.

“With marriage,” says Mary, “because young people can bespoke everything on their screen, they think they can bespoke their marriage. So this partner is irritating so let’s eject and try another one and of course the whole point is that life is full of joy and woe and, once you realise that it’s full of joy and woe and that it’s not non-stop euphoria all the way through, then in the long term, you’ve got a better deal. There’s lots to be said for continuity and everyone’s human. I have many friends who have ejected one husband and found the next one really annoying just as the first one was.”

Which means, I guess, that Giles and Mary are sticking with each other, differences and all. That will naturally entail Mary narrowing her eyes quite a bit at Giles, who, by his own admission, is part Basil Fawlty, part Alan Partridge and part Mr Bean, but it will also involve 25 mostly happy hours watching television every week. And could Gogglebox be good for the rest of us too? Mary and Giles think so. Switch on Twitter, they say, and all you see are the differences between people, but switch on Gogglebox and all you can see is how alike we all are, right across Britain: squirming at the same things, delighting in the same things, hollering and groaning together. It’s a sort of invisible national consensus, a reminder that, amid all the diversity, there’s a lot of similarity. Look at us: we’re different. But look at us: aren’t we all the same?

Giles Wood and Mary Killen will be appearing at the Boswell Book Festival at Dumfries House in Ayrshire on Sunday, May 6, at 5pm. For more information, see www.boswellbookfestival.co.uk