Gwyneth Paltrow scuppered her nice girl image this week after dropping the C word on a late night talk show.
The married Oscar winner called her own grandmother a C*%$£ after revealing the mum of her own mother hated her guts.
Speaking to Chelsea Handler - who, let's face it, is no stranger to a bad word or two- on her show, the blonde beauties realised they both had mean German grandmothers with the same first name.
Chelsea resorted to calling her grandmother a bitch, while Gwyn was bleeped blurting out the C word.
But although the word was bleeped out, viewers will still be able to see the star mouthing the word.
After the shock had sunk in the audience laughed and applauded the foul mouthed actress.
The mother of two then tried to justify her outburst by explaining her late grandmother was a spiteful woman : "She just hated my guts, basically, and she tried to poison my mother against me."
"She must not have been very happy and she must have had a lot of pain because she was as mean as hell."
Is Gwyn turning into a naughty girl?
Gywn has been trying to shake up her good girl image for a while now.
The 38 year old has admitted to wanting to duet with bad boy Rapper Jay-Z saying they would be a good combination.
She was also seen showing off her rapping skills on the Ellen Degeneres show last week, has already worked with the likes of Cee lo Green and is working on her own album.
We know Rihanna has already taken it but maybe Gwyn should call her album Good Girl Gone Bad.