Kylie Jenner and her new best friend Anastasia 'Stassie' Karanikolaou are heating up the internet today. New bikini pics of the two besties leaked on social media.

And folks all over are asking the question - which one of the buxom beauties - has the better body?

Kylie and Stassie are currently renting a gigantic super yacht, worth $250 million to visit Positano on the Amalfi Coast with her friends and family. Kylie is gearing up for her 22nd birthday today. 

Kylie Jenner looked incredible, her surgically crafted curves looked amazing - as she relaxed with her BFF on board the luxury vessel on Friday. 

But so did Stassie. Her body is equally as enhanced as Kylie's - only her proportions seems a bit more realistic.

Also on Kylie's mega-yacht is her beau Travis Scott, 28, daughter Stormi, 18-months, sister Kourtney Kardashian's ex Scott Disick, 36, and his girlfriend Sofia Richie, 20, along with 'momager' Kris Jenner, 63, her boyfriend Corey Gamble, 38.

The Kardashian-Jenner clan jetted out to Italy earlier this week, as they prepare to celebrate Kylie's 22nd birthday in spectacular fashion. 

Here are the images:

LINK TO FIRST IMAGE - rear shot

LINK To Second Image - Kylie booty side view

LINK To third image - side by side booty pics

LINK To Fourth image - front shot

It turns out that Jenner and Stassie go way back. ​Stassie has known Forbes' youngest self-made billionaire for nine years, with Stassie so close to Kylie Jenner that at one point she even moved into her home.

The pair also have matching tattoos that read 'Stormi' - the name of Jenner's child.

Previously the pair - along with some of Kylie's other close friends, including Sofia Richie - hopped on a private jet for a lavish holiday to the Turks and Caicos Islands to celebrate Jenner's new line, Kylie Skin.