The actress, who is the daughter of Greek actor John Aniston and late model Nancy Dow, reveals she was forced to entertain relatives every year with her belly wobbling skills.

"When I was a kid, they used to make me belly dance," she tells Entertainment Weekly. "My dad's side of the family is Greek, so I would dress up as a little Greek girl, and then on Christmas, after taking belly-dancing classes, I would do that. It had nothing to do with Christmas, even. It was just, 'Let's humiliate Jen on Christmas'."

And there was lots of travelling around the holidays as a kid: "My mom and I would go to Tavern on the Green (in New York City). We'd treat ourselves to a Christmas Eve dinner there. I'd wake up, spend Christmas with my mom and then I'd go with my dad to my stepmom's in Jersey.

"Then I'd go to my grandmother's in Pennsylvania and see all the Greeks. I travelled a lot of ground. And I looked forward to it. Especially when you got to the Greeks, because they're so much fun. And I did get a nice little stash of goodies."

Aniston is up to all sorts of kooky antics in her new raucous holiday comedy Office Christmas Party, which also stars Olivia Munn, Courtney B. Vance, Jason Bateman and T.J. Miller, and although she's elated to be part of the film, the star admits she didn't think she'd be cast as a joyless CEO.

"I've known about this movie for so many years," she reveals, "so I always was joking throughout the years, 'There better be a part for me in there.' And all of the sudden he (director Will Speck) was like, 'Hey, so we'd like you to play a part,' and I was like, 'Really?' It started off as a little cameo. It was supposed to be just a small little thing."

As for this Christmas, Jen just wants to be with husband Justin Theroux, adding, "I just want a beautiful shared experience."