WOW! Who owns that ass? Yet more fun and frolics in St Barts

The sisters are certainly marking the end of the summer in style with a luxurious trip to the Caribbean.

And while their elder sibling Kim has traditionally boasted the world's most famous derriere, it's clear that Mrs West, 34, now has a couple of contenders for her crown lurking in the wings.

Paragliding over the turquoise seas surrounding the French-speaking island of St Barts, 18-year-old Kylie Jenner showed off plenty of booty – but even that was nothing in comparison to Khloe Kardashian, 31, whose ass-ets were on full display. 

On the boat below were sisters Kourtney Kardashian and Kendall Jenner, as well as their young nephew, Mason Disick, five.

All this week, catwalk model Kendall, 19, has been particularly active on social media, sharing several incredible, envy-inducing snaps of the Kardashian-Jenner family trip. 

In shots from yesterday, Khloe can be seen in striking red swimwear, while Kendall also had opted for a one-piece – this time in black. 

Khloe rightly seems incredibly body confident during the beach break.

Indeed, she revealed earlier this month that since splitting from husband Lamar Odom in December 2013, she has shed an impressive 35lbs through better diet and a seriously dedicated gym schedule.

It has also been rumoured that Ms Kardashian's family are concerned for her safety in light on Mr Odom's rants about their relationship – and an apparent ambush outside her Beverly Hills gym last week. 

Khloe has been dating another professional basketball player – James Harden – for the last few months.

The Keeping Up With The Karadashians crew has been by the family's side for the entirety of their Caribbean trip – although a five-months pregnant Kim and momager Kris, 59, did not take part in the water-sports on offer this week.