American reality television star Kylie Jenner is reportedly unhappy with Kendall Jenner's growing fame and successful career at such a tender age.

According to InTouch, the 17-year-old Keeping Up With The Kardashians star is "bitter" over her elder sister's modeling success.

"Kylie is bitter that Kendall is doing better than her and it's driven a wedge between them," a source told the publication, via Radar Online. "They barely speak," the source added.

The 19-year-old model was named the new global face of Estée Lauder in November last year.

"Kendall is jet-setting around the world with her celebrity friends while poor Kylie is at home moping around," the insider added.

"She feels like the black sheep of the family," the source said. "And completely left out."

However, Hollywood Life reported that there is rivalry between the siblings.

"Kylie has never been interesting in modeling as she feels like that is Kendall's thing," a source told the website. "Still, she will do it from time to time if offered especially if it is artistic and cutting edge. She's not interested in doing the standard fashion magazine shoot."

It was previously reported Kendall's half sister Kim Kardashian is also envious of her.

Kendall had earlier revealed that she banned Kanye West's wife to attend her runway shows.

"Kim was invited to a lot of the shows that I was in," she said, according to The Cut. "She called me before and was like, 'Hey, I was invited to the show, I just wanted to let you know. Do you want me to come?' and I was like, 'No'," she was quoted as saying.