We're not used to seeing Jennifer Aniston looking dowdy by any meaning of the word.

But as she was forced to wear a frumpy blouse on the set of new film Meet The Millers, Jen couldn't resist raunching it up a bit by undoing her shirt and flashing her bra.

jennifer aniston

The newly engaged star showed off her seriously tanned and toned stomach as she chatted with the film's crew in between takes.

jennifer aniston

The film tells the story of a veteran pot dealer who creates a fake family as part of his plan to move a huge shipment of drugs into the US from Mexico.

She was also seen wearing a ring on set, but it is unknown if it is her engagement ring from Justin Theroux or just for the role.

jennifer aniston

Meanwhile, it has been reported that Jennifer may have got engaged six weeks ago.

It had been thought Justin proposed to Jen on his 41st birthday earlier this month, but Heat magazine has claimed the couple first got engaged during a trip to Italy in July.

A friend told the magazine: "They kept his proposal to themselves because they wanted to wait until he had the ring, and also they wanted to make a formal announcement when they were ready.

"Justin also wanted to tell his ex-girlfriend [Heidi Bivens] in person, so she didn't find out from the press."

They added that the formal engagement on 10 August was pre-planned.

> IN PICS: JENNIFER ANISTON'S STYLE EVOLUTION

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  • 1998

    Jennifer Aniston wears a white t-shirt, black blazer and flat cap on backwards.

  • 1998

    Jennifer Aniston wears a full length figure hugging dress.

  • 1999

    Actress Jennifer Aniston wears a gown with detailed top for the Emmy Awards.

  • 2001

    US actress Jennifer Aniston arrives at the premiere of <em>Snatch</em> wearing a khaki green scarf and white t-shirt with a brown leather jacket and jeans.

  • 2002

    Actress Jennifer Aniston arrives with then husband Brad Pitt at the Golden Globe Awards. She wore a blazer jacket with short necklace.

  • 2002

    Jennifer Aniston wore a pink embellished gown at the Emmy Awards.

  • 2002

    Brad Pitt and Jennifer Aniston at the premiere of <em>The Bourne Identity</em>. She wears a loose navy top.

  • 2002

    Actress Jennifer Aniston wears casual cargo trousers with a navy vest.

  • 2002

    Actress Jennifer Aniston wears a floral dress over black trousers.

  • 2003

    Jennifer Aniston wears a floor-length dress with cut-out detail.

  • 2004

    Actress Jennifer Aniston wears a strapless cream dress with embellished detail.

  • 2004

    Actress Jennifer Aniston wears a simple black dress.

  • 2007

    Actress Jennifer Aniston wears a cream dress.

  • 2010

    Jennifer Aniston launches her debut fragrance wearing a short strapless cream dress.

  • 2011

    Actress Jennifer Aniston wears a printed dress with black tights and shoes.

  • 2012

    Actress Jennifer Aniston arrives at the premiere of <em>Wanderlust</em> wearing a fitted dress.

  • 2012

    Jennifer Aniston wears a floral dress on the Hollywood Walk Of Fame.