Celebrity Gossip's

Kim Kardashian has shocked her family members by gulping down her sister's breast milk.

The 30-year-old socialite took a swig from a bottle full of Kourtney’s milk after being egged on by her siblings.

'It's sweet, it's good,' said Khloe Kardashian, who had previously tasted the liquid. 'If Mason can drink it, I can drink it baby.'

'Seriously, my breast milk tastes like vanilla soy milk,' Kourtney encouraged, before Kim vowed to try it.

Kim looked as if she was having second thoughts as Khloe, 26, approached her with the bottle and asked stepsister Kylie Jenner to do the pouring instead.

While her siblings chanted 'chug it', the socialite took a small sip and grinned with delight.

'Welcome to the fit club baby,' Khloe declared.

The hilarious breast milk scenes were shown on the family's reality TV show, Keeping Up With The Kardashians.

Viewers were even treated to a preview of spin off show, Kourtney and Kim Take New York, which premieres next month.

One scene showed Kim being held upside down by a group of people – including her own mother – as she drank from a beer keg to celebrate turning 30.