Kylie Jenner "hates" living in Kendall Jenner's shadow.
The 17-year-old reality TV star reportedly finds it frustrating that her 19-year-old sister - who is a successful fashion model - is doing so well.
Although the brunette beauty recently launched her own hair extension line, she still feels envious of Kendall - with whom she starred on 'Keeping Up With The Kardashians' - and just wants to do her "own thing".
A source told RadarOnline.com: "Kylie is always going to be playing second fiddle, and she absolutely hates it."
The pair are said to have clashed while launching their new range of summer clothing for PacSun and Kylie is desperate to make herself a name in her own right, away from her famous family.
The insider added: "Kylie is just trying to do her own thing right now and develop a brand for herself that will outlast Kendall's minute of fame."
Meanwhile, Kylie's newly enlarged lips have been keeping her in the spot light in recent weeks after she confessed to having temporary fillers to plump up her pout.
Her half sister Khloe Kardashian, 30, is now said to be "jealous" of her younger sister's look and has resorted to undergoing the procedure herself to compete.
A source said: "It does make her a little jealous. Khloe has been getting fillers in her face and in her lips for a while. She just does the bare minimum because she doesn't want to look like she's had anything done.
"The last time she went, she got a little extra filler in her lips, way more than she normally does, and that's totally because of Kylie! She sees how great Kylie looks and how much attention she's getting from guys, and she wants that, too."