Kendall and Kylie Jenner reveal their biggest fear

Keeping up with the Kardashian’s stars Kendall and Kylie Jenner spoke about their new fashion line for TopShop and their biggest fears in a new interview with Britain’s Sunday Times’ Style Magazine.

The teen stars told the magazine, which features the two on the May 31st cover, their biggest fear is growing up and getting older.

"I'm scared of the day I turn 19," Kylie, 17, said. "I really don't want to grow past 18. You'll be 20 this year — that's crazy,” she added, acknowledging her sister. “And any second you'll be, like, 21, 22, 23..."

Kendall agreed, saying, “Life is scary.”

The runway model also said, "It's just scary to think how fast everything is rolling and you can't stop it. It's rolling right now. You see a picture and you've changed so much in a year."

Kylie, who recently admitted to getting temporary lip fillers said, "I've done so much, physically and whatever,"

The fashion designers are some of the biggest celebrities on social media, but the girls say social media is not as important as their generation thinks.

"I think social media has taken over for our generation," Kendall said. "It's a big part of our lives and it's kind of sad. I hate it sometimes. I literally want to throw my phone so I can't look at it. It's all a made-up world if you think about it. Social media…this interview, everything. It's not real. It's pretty crazy.”

Image courtesy of Kristin Callahan/ACE/INFphoto.com