This week on 'Keeping Up With the Kardashians', Kim, Khloe, and Kylie reveal their deepest insecurities, and Kendall questions why anybody needs to have anything done since all of them look beautiful as they are.

Kim and Kendall accompany Khloe as she had a cosmetic procedure to get rid of her cellulite and stretch marks, and Khloe says "When you are photographed all the time, it's natural to have insecurities or to want to change certain things about yourself."

Over lunch, talk turns to Kylie's lips, and while Kim and Khloe are supportive about their youngest sister's decision to change her look, Kendall appears to be less enthused about it, saying, "I just don't want her to take it too far. She's a beautiful girl."

Meanwhile, Kylie decides to come clean about her lips after being hounded by the press for more than a year about her new look. Previously, the 17-year old attributed her pout to expertly applied lipliner, but now she says, "I have temporary lip fillers. It's just an insecurity of mine, it's what I wanted to do."

Later, Kylie talks to Kim and Kendall about her insecurities, and Kim says that she understands what Kylie is going through. Kim admits that she's insecure about her psoriasis as well as her weight—so much so that she has taken to wearing Spanx every time she leaves the house. She tells Kylie that she needs to be proud and own up to what she has done, but warns her not to get too carried away. Kendall says that she has no idea why everyone is "talking about this."

"No one needs anything—everybody's beautiful," said Kendall.

After talking to her sisters, Kylie tells the cameras that she feels ready to stop tip-toeing around the truth and to just let go of her insecurities.

"We all have eyes on us all the time," said Kylie. "Especially for me, at my age, trying to find myself. It's hard not to let it affect you. Having older sisters with some of the same insecurities as me helps me a lot and makes me feel like it's okay."

'Keeping Up With the Kardashians' airs on Sundays at 9pm ET on E!