Kendall Jenner Upstages Kim Kardashian's 'Booty Selfie'

Kendall Jenner is becoming more and more like big sister Kim Kardashian every day.

The 18-year-old aspiring model photobombed Kim's intended selfie of her famed backside on Friday.

"Barging in on Kim's booty selfie," Kendall captioned herInstagram picture, which showed both sisters showing off their assets in sports bras and tight, black workout pants while at the gym (Kim's face is obscured by her phone).

Kim, 33, has been posting numerous pictures of her body since giving birth to baby North last June.

After being accused of photoshopping her photos to make her waist appear smaller, the new mom took to Twitter on Friday to defend herself.

"It sucks when people make up surgery or photoshop lies when I am so disciplined & work so hard!" she wrote. "Just trying to motivate others & show anyone struggling with weight they can totally achieve whatever they want if they are dedicated!"