CHRISTMAS is merely weeks away, and with thoughts turning to gift buying, you have to feel for Jennifer Aniston's fiance, Justin Theroux.

What do you buy one of the most famous women in the world, whose net worth is estimated to be around $150million?

"Oh, I'm easy to buy for - the littlest things, like gestures of love," says Aniston. "Who needs more things? You know, just write me a nice card," she smiles.

The actress, wearing a black pencil skirt and sleeveless 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 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, has resulted in people questioning 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."

Having shot to global fame in Friends 20 years ago, she tries not to let the 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.

Aniston played one of those bosses, nymphomaniac Dr Julia Harris. a 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."

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,

It's a far cry from her forthcoming movie Cake, which is creating an awards buzz following a standing ovation at the Toronto Film Festival.

Aniston plays a woman coping with chronic pain who initiates a dubious relationship with a widower while concocting hallucinations of his dead wife. Ahead of filming, she 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: "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."