The rumor mill has been busy for months speculating about Kylie Jenner's fuller lips. Young girls across the Internet have tried to mimic her look by taking the Kylie Jenner Challenge -- suctioning a glass bottle over their lips to achieve swollen and bruised lips.

The 17-year-old has insisted that she uses lip liner to make her lips look fuller.

In the upcoming Episode 9 of "Keeping Up with the Kardashians," an interview about Kylie's new line of hair extensions suddenly takes a different direction when the interviewer asks about her plumped lips for the first time.

Caught off guard and not knowing how to answer, Kylie asks older sister Khloe Kardashian, 30, for advice. Kylie prefers not to confirm or deny the rumors, and she doesn't have to as Khloe makes the big reveal for her.

"Kylie decided to get her lips plumped," Khloe announces in the sneak peek video clip. Unlike Kylie, Khloe thinks "it is right to cop up to it."

Khloe will do her own "copping up" in this week's "KUWTK" when it comes to cellulite and stretch marks. Kim Kardashian, 34, and Kendall Jenner, 19, will accompany the star to a medical office, where Khloe receives a laser treatment to zap away stretch marks and cellulite on her posterior.

"It stings like a mother," Khloe says in the promotional video clip.

Kim and Kendall aren't much support. They are distracted by a fancy dessert cart presented by the doctor. The sisters enjoy the delicious morsels while Khloe has the painful procedure done.

Meanwhile, Kourtney Kardashian, 36, has partnered with longtime boyfriend and the father of her children Scott Disick, 31, to remodel houses. She takes the role of interior designer on a house he's attempting to flip, but her expensive tastes has Scott wondering if she's a good business partner.

Watch "Keeping Up with the Kardashians" Episode 9 on Sunday, May 10, at 9 p.m. ET on E!

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