Kylie Jenner's lips have become somewhat of a phenomenon over the past year or so. The 17-year-old Keeping Up With the Kardashians star refused to admit to lip injections until it was pretty much impossible for her not to – and Khloé Kardashian doesn't think there's anything wrong with that.

During her recent interview with Complex, the youngest Kardashian sister said that Kylie was incredibly insecure of her lips, and it was even preventing her from being comfortable in front of the camera.

"Sometimes things bother her. When it comes to her lips, I knew it was one of her biggest insecurities. She used to always take pictures covering her mouth," Khloé said.

"I didn't even know when she first did her lips. It wasn't noticeable, then it started getting bigger and bigger. I guess that was something she just wanted."

How nice it must be to live in a world where a teenage insecurity is reason enough to alter your body. Sigh.

In just six short years Kylie's lips have gone from thin to luscious, and she's not even 18-years-old yet! Click through the gallery to see the evolution of her lips, and leave all your burning thoughts and feelings in the comments.