IT MIGHT be a chilly day, but that doesn't stop Thomas Turgoose baring his backside – much to his co-star Andrew Shim's amusement – while Joseph Gilgun is busy sharing his irritation at his routine toilet habits being disturbed.
Watching on nearby, Vicky McClure, wrapped up in a coat and sipping a tea on the double decker canteen bus, just shakes her head with the weariness of someone tolerating their wayward siblings.
"A lot of us grew up together, so it's warts and all. There are arguments too, never long ones, but we spend such intense time together," says the 32-year-old actress.
We're on the set of This Is England '90. It's the final instalment of Shane Meadows' landmark TV series, which emerged from This Is England, the 2006 film inspired by Meadows's own experiences in the early Eighties.
Channel 4 aired This Is England '86, co-written by Jack Thorne, in 2010, and then This Is England '88, a three-part Christmas special, followed a year later.
The latter wasn't exactly full of festive cheer though, as the film-maker has an unapologetic, no holds barred approach to bleak subject matters.
"Shane is unique. He's brave in the way he shoots things, to make the viewer feel uncomfortable," notes Nottingham-born McClure, who plays Lorraine 'Lol' Jenkins.
In '86, Lol killed her abusive father Mick (Johnny Harris), after discovering he'd attacked her best friend Trev (Danielle Watson) and later attempted to rape her when she confronted him about it.
"There were lots of things me and Johnny did in preparation for a scene like that. It felt like hell, but that's what it needed to be," says McClure, who won a TV Bafta for the series, while Harris, now one of her closest mates, was also nominated for an award.
"It was an honour to be thought of and an honour to win it! [I was] Definitely the underdog, and I enjoyed that moment," she adds.
In '88, Lol attempted suicide, traumatised from years of abuse and battling with the guilt of her mate Combo (Stephen Graham) taking the blame for her.
"To try and even begin to do the hurt, disgust and pain justice, you have to send yourself into a dark space. I was trapped in my own little head," continues the actress. "But during '90, I haven't needed to do it."
That's because, by the time the credits rolled on '88, there was finally a sense of hope for Lol, when she was reunited with her childhood sweetheart Woody (Gilgun). And when the new series opens in the spring of 1990, they're revelling in domestic bliss.
"We're happy and together, and have a family and a house," explains McClure, who also worked with Meadows on 1999 film A Room For Romeo Brass.
Woody's in his element as a stay-at-home dad, sharing the fun with his best mate Milky (Shim), while Lol flourishes working as a dinner lady with her mum, sister and Trev.
"She is content and happy, and with a new family set up she shares with Woody. They've got a baby together, and she's got her daughter with Milky and somehow, it works. So that's how you see her first off – it's a happy little family."
Woody and Lol still have their moments though, and "when they happen to argue in a scene, we'll get in a mood with each other as Vicky and Joe", adds McClure, laughing. "Then we finish work, go out for something to eat and it's no big deal."
This time, there's a split between the younger members of the gang, including Shaun (Turgoose) and Harvey (Michael Socha), and that was reflected off set.
"'86 was crazy because we all lived in a set of flats together, so we were literally next door to one another. It was carnage, but brilliant carnage. We needed that to re-bond [after the film] and get into each other's lives a bit more," recalls McClure.
"This time, it was kind of weird, because we'd go out and I'd say, 'Shall we stop now and go home?', and they said, 'No, let's stay out!' It was nice and absolutely reflects what happens in the show."
For the first time, there were no rehearsals or read-throughs before shooting began. "We were pretty much let loose this year," remarks McClure. "Everybody knows their characters better than we've ever known them."
But that didn't stop nerves creeping in.
"We're going back on to a really successful show and we want to do it justice," she explains. "There was one particular scene, that I won't spoil, but it took everyone to really knuckle down.
"It's a long scene, with a lot of characters, and it was one of my proudest moments. I was desperate to ask for some advice, and Shane said, 'I'm not going to talk to you, I'll let you do your thing'. It was frustrating but he trusted me, and I think he got what he needed."
Unlike other projects, there's no need to worry about the cameras, or getting their positions completely right, "and there's no fussing about with the set and lighting".
"The beauty about this is you can be trusted to create this character," explains McClure. "We love nothing more than just being able to improvise."
But, she adds, "every method has its place".
"I do other shows, like Line Of Duty, that are more structured. I couldn't improvise that, even if I wanted to. The scripts are so incredible and I'm not a copper, so I don't have the lingo."
McClure was working in an office when the original This Is England was shot. "I took six weeks off to do the film, and then nothing happened for such a long time. I had [acting] jobs here and there but no career."
It was only when '86 came along that she decided to take her chances.
"Since then, I've not had to rely on another source of income and, every day, I'm so grateful."
As the final chapter of This Is England draws to close, she admits she'll miss working with the gang and bringing Lol and Woody to life.
"Someone tweeted me that we're the Kate and Wills of the working class. I'm a sucker for a love story," she adds. "Everyone is."
:: This Is England '90 begins on Channel 4 on Sunday.
