Sisters who party together, stay together.

Kylie Jenner and her sister Kendall were spotted partying at the exclusive Loulou’s beach club in St. Tropez on Thursday.

Photos obtained by Page Six showed the siblings enjoying some fun in the sun as they took a quick dive in the clear blue waters with a group of friends.

Kendall, 29, was seen rocking a tiny black bikini, which she covered with a black and white polka dot printed mesh mini dress. She paired the ensemble with a pair of black shades.

As for her hair, she styled her black locks in a half up, half down look.

The Kylie Cosmetics founder, 27, on the other hand, was the yin to her sister’s yang in a white skin-baring one-piece swimsuit. She covered her lower half in a flowy white mini skirt.

Kylie additionally let her long black hair hang down her back as she made herself comfortable in the ocean water.

They were accompanied by at least three other women for the beach outing.

This new sighting comes amid the sister’s continued vacation in Tuscany after they attended Jeff Bezos and Lauren Sanchez’s highly anticipated wedding last weekend.

On Thursday, Kylie showed off her curves in a different — but equally flattering — animal-print two-piece while snacking on a bowl of cherries and sipping on some white wine.

In a carousel of photos shared to her Instagram, the Khy founder showed off her swimsuit set, which appeared to be part of her forthcoming Frankie’s Bikinis collaboration.

The “Kardashians” star announced the partnership Wednesday by sharing a social media video of herself shaking hands with Frankies Bikinis founder Francesca Aiello.

However, the collection’s official launch date remains unclear.

Kylie was also recently seen exploring her luxurious Italian resort in multiple chic swimwear looks including a floral bikini top and matching scarf, which also could be part of the new collaboration.