"I'm a little Diva"

But while many milestones have already been reached in his short career, it was only recently that the 25-year-old fulfilled one particular rite of passage; the dreaded sex scene...

"They're anything but sexy, with all those big hairy men surrounding you... That sounds so weird," says Irvine, laughing.

The Cambridgeshire-born actor filmed the steamy scenes with "very cool Australian actress" Hanna Mangan Lawrence for new thriller Beyond The Reach, which also stars Michael Douglas.

"You just have to make a joke of it. What you're doing is so ridiculous," the rising star adds.

The idea of his profession being "ridiculous" comes up quite often when chatting to Irvine, who grew up the eldest of three sons to Bridget, a local politician, and engineer Chris, in the village of Gamlingay.

Much as he enjoys what he does, acting is, he states with a laugh, "inherently stupid and embarrassing".

"As a grown man, I'm going to work every day playing make-believe and dressing up," he adds with a shrug.

Back in 2012, when War Horse - in which Irvine played the lead character Albert - was up for a string of Academy Awards, he declined the invite to the glitzy ceremony.

"At the time, I just found those things so uncomfortable," he explains, noting that he doesn't regret his decision. "It wasn't that I'm against them, they're great, and it's such a laugh now that I know people, but I'd never been out to America before and I didn't know anyone out there.

"Also, there is something weird about them. My mum used to work for a charity re-housing homeless people and she doesn't get big, fancy award ceremonies. I think I felt quite guilty," Irvine continues. "I didn't feel like I'd done that much to be flown first class around the world... But now I'm a little diva and I love it!"

Part of his change in outlook came about after chatting to his Railway Man co-star Colin Firth.

"I think his words were, 'Just treat it like a big romp'," recalls Irvine, who despite labelling himself a "diva", is actually very unassuming and makes for friendly company.

"You can be too cynical. Now when I go to Cannes, I take my mates with me and they all sleep on the floor of the hotel room and we turn it into a boys' holiday. There's a lot of fun to be had out there."

Top of his fun list recently was making Beyond The Reach, which saw him spend "two months in the desert with Michael Douglas".

Irvine plays young trekker Ben in the movie, who embarks on a dangerous hunting trip in the Mojave Desert with wealthy businessman Madec (Douglas).

Like with Firth, working with the 70-year-old Hollywood star left a lasting impression on the young actor.

"Michael said that he loves that feeling of flying by the seat of his pants, being slightly out of his depth and having to really go moment by moment. It is a very exciting way to work," says Irvine, who is also writing a history documentary about WW1 and WW2 with his friend, inspired by the veterans he met while researching his period roles.

"He's got this real excitement that I think is the same for people like Steven Spielberg," he continues. "All these people who've had incredible careers, all have this real love of what they're doing, hence why they've had really incredible careers."

Eager to throw himself into roles, Irvine lists learning how to ride a horse and motorbike, scuba diving and rock climbing as new skills he's amassed as a result of his work. Admittedly, those were among the more fun challenges he's undertaken.

"I've only one phobia, which is rats, and in War Horse they released about 200 rats into the trenches in one scene," recalls the actor, who studied at London Academy of Music and Dramatic Art and appeared in Disney Channel sitcom Life Bites in 2009 before Spielberg cast him, propelling him towards the big time.

"I had real trouble with that and was really trying hard not to show it. I really didn't want to look like a wimp in front of all the other actors."

While he had previously worried about filming sex scenes, he admits that Jonathan Rhys Meyers, his co-star in upcoming gay rights film Stonewall, made his second round of on-screen bedroom liaisons just as easy as Mangan Lawrence did.

"I was literally lying on my back with Jonathan Rhys Meyers over me," he says, laughing. "He was just going, 'Look man, to be honest, I did this 10 times a day when I was in The Tudors'. [But] I assume that our scene was the best one he's ever done."

Jokes aside, the film's subject matter is something Irvine is passionate about.

Playing a young man who is caught up in the 1969 Stonewall Riot, a protest in New York to promote equal rights for gay people, Irvine hopes the film will have wider reaching consequences.

"Every now and again, you get to do a movie that's more than a film, and I think that one felt like a story which really needed to be told," he says.

"I actually didn't know about the Stonewall Riot, which is shameful really. I think it got lost within the Civil Rights Movement, because it was all happening during the same summer, the same year."

He doesn't think equality has been achieved yet, but thinks "things are moving in the right direction".

While it's been "shocking" for Irvine, who grew up "around liberal people and in such a liberal profession", to travel to places where homophobia is still rife, he relishes being able to explore the world and keep pushing himself to experience new things.

"So much of it [acting] is about bluffing it until you get through," he says. "I quite like the idea of 'fake it 'til you make it'. When they [the War Horse crew] asked whether I could ride a horse, I was like, 'Sure I can ride a horse!', and then was like, 'I'm going to have to learn to ride a horse in a week!'

"You do your best. Sometimes it works, sometimes it doesn't."

:: Beyond The Reach is released in cinemas and on VOD on Friday, July 31