Sisters Kylie and Kendall Jenner. (Picture: Instagram)

The 'Keeping Up With The Kardashians' star has teased the prospect of working on a beauty collaboration with her sibling but they couldn't before because Kendall was in a longtime contract with make up brand Estée Lauder.

When someone asked Kylie if she could collaborate with her sister during an Instagram live question and answer session, she simply held her finger up to her mouth and said, "Shh", prompting speculation one is in the works.

She added: "You know Kendall was in a contract for a really long time so I couldn't do a collaboration with her. That's the only reason why I didn't collaborate with her. But, you know, we worked it out."

Kylie's cosmetics brand has gone from strength to strength and is loved by her fans, friends and family alike.

Her half-sister Khloe previously confessed she keeps five Kylie Cosmetics lip-glosses in her make-up bag at any one time, adding: "I have five [Kylie Cosmetics] colours in my make-up bag. The 'Koko K' shade is named after me - that was a surprise. It's a pinky nude, which is what I wear every day."

Kim Kardashian West's make up artist Mario Dedivanovic is also a fan of the brand and he "hoards" as many as he can,

He said: "I'm the biggest hoarder of Kylie Cosmetics. I literally have boxes and boxes at my house that I'm collecting.

"They're just so iconic I want to keep them forever. Her black gel eyeliner is so good and is in my kit a lot."