Kim Kardashian pouts with her plump ‘pregnancy lips’…

The previous day Kim Kardashian posted a photo of her more pronounced pout due to 'pregnancy lips'.

But the 34-year-old reality star's youngest sister may have her beat when it comes to the battle of who has the larger lips.

Kylie Jenner posted alongside her much older sibling in a photobooth snap shared by Kim from James Harden's 26th birthday bash aboard a yacht in Marina Del Rey, California late Tuesday night.

 Pucker up: Kylie Jenner appeared to have a significantly plumper pout than older sister Kim Kardashian as they posed together in the photobooth at James Harden's yacht party in Marina Del Rey on Tuesday night

 Luscious: The previous day the 34-year-old reality star posted a photo commenting on her 'pregnancy lips' as they appeared to be in fuller firm

The recently-turned 18-year-old reality star appeared to have much bigger lips as they posed to Kim's rapper husband Kanye West in the black and white photo.

The teenage star has previously been criticised for having lip injections at such a young age before finally admitting recently that she had the cosmetic procedure done.

'I have had temporary lip fillers,' she said in an E! clip from an episode of Keeping Up With The Kardashians aired in May.

Battle of the bulge: The 18-year-old youngest of the Kardashian-Jenner clan appeared to still have much bigger lips despite Kim's social media comments the day before

 Where's the birthday boy?: Kylie, Kendall, Kourtney, Kim and Khloe were all in attendance as they posed with NBA superstar birthday boy James who hid in between the two tallest members of the family

On Tuesday, Kim posted a series of photos from a hike with mother Kris Jenner in St Barts where her pout looked a bit fuller than normal.

She captioned the shot: 'Pregnancy lips' which many of her followers commented on saying: 'That's not even a thing!'

However many women do find their pout inflates with pregnancy, due to water and fluid retention, giving them the look of someone who has had artificial injections.

'K2': Kim and 19-year-old model Kendall posed together in a much less crowded photo

 Sisterly love: Kendall and  Kylie cuddled up for a cute snap together

Kim has spoken out about her swollen lips before - when she was pregnant with daughter North, she posted photos of her pout on Twitter.

She captioned the shot: 'My pregnancy lips are outta control #IGuessNotABadProblemToHave.'

The photo featuring Kim and Kylie's best puckers alongside the 38-year-old rapper was just one of the photos shared on social media by America's favourite reality television family.

 Photobooth fun: Kylie shared this photo as she was was joined by her rapper boyfriend Tyga, sister Kim Kardashian and an unusually cheery Kanye West

 Tremendous trio: Eldest sister Kourtney Kardashian took to the picture-sharing social network to post this photo of her being flanked by Kendall and Khloe

 Keeping up: Kourtney, Kendall, Kim, Khloe and Kylie posed for an all sister snap together