'I would like a day of being invisible'

"Oh, I'm easy to buy for - the littlest things, like gestures of love," says Aniston. "Who needs more things? I'd rather give that money to the people who need it. You know, just write me a nice card," she adds, gesturing with her hand as she speaks, inadvertently flashing the rock of an engagement ring on her finger.

The actress, wearing a black pencil skirt and sleeveless pale pink top is looking fresh-faced despite the jet lag. And yes, her face does move. There are even faint frown lines, which is rare these days in Hollywood.

She's just flown in with her Horrible Bosses 2 co-stars Jason Sudeikis, Charlie Day and Jason Bateman, for the UK leg of the film's press tour - and is having a blast. "Jason called it 'movie camp' on the plane here. We saw Benedict Cumberbatch and all descended on him and I think he signed up for the third movie. I'm announcing it right here," she jokes.

Fresh from LA, she confesses she's having trouble getting her head around the fact Christmas is almost upon us. "It is so hot out there at the moment," says the 45-year-old, who lives on the West Coast while Theroux is based on the East, shooting TV series The Leftovers.

Just as was the case during her marriage (and subsequent divorce) to Brad Pitt, and ensuing relationships with her The Break-Up co-star Vince Vaughn and singer John Mayer, their bi-coastal set-up has been the subject of immense dissection.

Even the fact they haven't announced a wedding date despite being engaged for two years, after meeting on the set of 2012's Wanderlust, has resulted in people questioning the status of their relationship.

No wonder Aniston admits there are times when she craves anonymity.

"I do, is that terrible?" she asks. "But I think anybody under that microscope would like a day of being invisible." She pauses for a second, then adds: "None of it's true. You know what your life is like and you know what happens when you go home and shut the door and hang with the dogs and hang with the boyfriend."

Having shot to global fame as Rachel Green in Friends 20 years ago, she tries not to let the headlines and global tittle-tattle affect her, but admits "it's taken time to thicken up my skin in terms of what people project on to me".

"Finally, after years and years of people saying, 'Don't pay attention to it', a few years ago, I finally started abiding by that," she adds.

It was about that time she signed up to 2011's Horrible Bosses, a comedy about three guys who devise a plan to bump off their monstrous supervisors, but mess up at every turn.

Aniston played one of those bosses, nymphomaniac Dr Julia Harris. Known as Hollywood's 'good girl', her casting left jaws on the floor, which is exactly why she couldn't wait to return to the role of the filthy-talking dentist.

"Honestly, that role is a treat and they don't come along very often, not for me, especially. They were unsure I'd even say yes and I couldn't even believe they offered it to me, so I was psyched about coming back."

In the sequel, Dr Julia appears to be making strides towards conquering her demons and is even offering up her own office as an after-hours meeting place for her therapy group.

"She's trying to better herself," explains Aniston. "She's in a sex addiction group and we're thinking she's doing pretty well this time."

But, it transpires, she's actually using the get-togethers as a chance to find new partners in crime.

"I think she knows that everyone at those meetings is pretty vulnerable and on the verge of falling off the wagon, so for her, it's another avenue for flirtation. She's not well, she's just not.

"But to her, there's nothing wrong or deviant about herself. She describes sex and approaches it as a chef would approach a wonderful meal to be made. It's like sport."

She might've spouted some filth in the last movie but she outdoes herself this time around, not least in a scene with her good friend Bateman.

"After take one or two, you get over the shock of saying things, especially to one of your friends of over 20 years. You stop blushing and feeling embarrassed, and then it's pretty fun and silly. I think we were just trying to out-squirm each other," admits Aniston, whose own worst job, she reveals, was telemarketing. "I was trying to sell timeshares. And I stress trying - I never managed to sell one."

Since starring in the original movie, the A-lister, who was born in California and introduced to the acting world early on by her actor dad John and godfather Telly Savalas, has appeared in the comedies Life Of Crime and the comedy We're The Millers, alongside Sudeikis.

But it's her upcoming movie Cake which is creating awards buzz, following its debut at this year's Toronto International Film Festival where it received a standing ovation.

Aniston plays Claire, a woman coping with chronic pain who initiates a dubious relationship with a widower while concocting hallucinations of his dead wife. Ahead of filming, the actress, famed for her honed physique, stopped working out so she could gain a few pounds, and in the movie sports a make-up-free face and unwashed hair.

It's Aniston as we've never seen her before, and, she agrees, "a world away [from Horrible Bosses 2], that is for sure".

"It was such an extraordinary experience and the hardest thing I'd ever done creatively thus far, but on a personal and creative level, it was so important to me. I have been dying to do something like that for a long time."

It was back in 2002 when she received acclaim for her performance in the drama The Good Girl, opposite Jake Gyllenhaal, after which she became the go-to for romcoms.

She wasn't alone in that. Texan Matthew McConaughey was doing a similar thing and has since made moves as a more serious actor. So perhaps, just as McConaughey did earlier this year for his role in Dallas Buyers Club, it's time for Aniston to have her moment and walk off with an Academy Award.

"Yes, comedies are one aspect of what we do, but as actors, there's an arsenal of stories we want to tell, and characters that we have inside of us, and sometimes, just certain ones get accessed," she notes. "In the last couple of years, I've been having a real fun time. I think, starting with this, where I could disappear a little bit and get into a character."

And as for the awards buzz: "That would be so lovely," she says, clutching her hands to her chest. "But I honestly don't think of it in terms of accolades."

EXTRA TIME - MAKING THE MOVIE

:: Director and co-writer Sean Anders has revealed that two or three takes would be script-led and then he'd let the cast "go nuts".

:: Jamie Foxx returns to the role of freelance crime consultant and world's worst negotiator Dean 'MF' Jones, while new recruits include Chris Pine and Oscar-winner Christoph Waltz.

:: The big chase towards the end of the movie is an amalgam of practical effects and green screen. Thomas Robinson Harper, stunt coordinator from The Matrix Reloaded, was brought in to help.

:: The movie was shot around LA, including at Licha's Bar and Grill where MF holds court, the Trump International Golf Course and the train crossing in San Pedro.

:: It was shot before Jason Sudeikis became a dad in real life, and he admits he felt overwhelmingly nervous when asked to hold the baby triplets brought in for filming.

:: Horrible Bosses 2 is released on Friday, November 28