That is one booty-ful photobomb.
“Barging in on Kim’s booty selfie,” Jenner, 18, captioned the Instagram shot she posted early Friday.
The duo certainly look ready for a workout: The sisters are both sporting figure-hugging black workout pants and sports bras. Kardashian, 33, is also wearing black Nike sneakers, while the flash blocks out her face.
She also recently made it clear that her hard work at the gym is responsible for the return of her famous figure – and nothing else.
“It sucks when people make up surgery or photoshop lies when I am so disciplined,” she wrote on Twitter Friday.
Also not new for the reality star? Appearing in amusing photos with family and friends, as evidenced by this sweetly dorky Throwback Thursday photo released this week, featuring Kim and pal Nicole Richie at 13.