Kylie Jenner Sucks Kendall's Tongue Because Sisterhood Is a Deeply Personal Experience

It's sister stuff.

They may fight sometimes, but Kylie and Kendall Jenner always have each other's backs -- and sometimes even each other's tongues.

Kendall Snapchatted herself sticking out her tongue at her younger sister on Monday, who decided to slurp it right the hell up.

WATCH: Kourtney Kardashian Strips Down in NSFW 'KUWTK' Season 11 Super Tease and Looks Amazing!

Right. The hell. Up.

"She sucked my tongue... I'm dead," Kendall captioned the snap.

Meanwhile, the reality star siblings are having an eventful trip down under in Australia, where they appeared at a Sydney mall to this kind of fandom:

WATCH: Kylie Jenner Has Panic Attack After Kendall Abandons Her on the Red Carpet

"I love you sweet Sydney. So much love in the air today," captioned the deafening video.

The trip did have its hiccup , their meet and greet was delayed 45 minutes when one woman allegedly threw eggs and tomatoes, a source tells ET. However, Kylie tweeted she knows nothing about any egg throwing.

She followed up the tweet, "I love you guys so much and we felt the love from you guys too ? Australia is one of my favorites so far."

WATCH: Kendall Jenner Gets Into Heated Altercation With Kylie: 'You're the Biggest F**king B**tch I've Ever Met'


At least the sisters have each other, no matter how many expletive-filled fights they have! As Kylie noted in this sure-to-be throwback Thursday-worthy shot, "I'll always be here for you my sister."

Aww! Sisterhood is beautiful!

Also, Kylie took the opportunity to show off her super toned tummy with a mirror selfie.

WATCH: Kendall Jenner Poses Topless: I'm Washing Away My Sins

Daang, Kylie!

As much as they love each other, Kendall and Kylie are not without their drama. Watch the 20-year-old model slam her 18-year-old sibling on the Keeping Up With the Kardashians premiere below.