Kelly Osbourne has got some serious back.

The E! fashion critic, 28, posted a revealing look at her derrière on Friday.

“It’s not a #FullMoon but it feels like one! Good luck everyone tonight!” read the caption.

In the snapshot, Osbourne sports her signature purple ‘do, a black top and a pink thong. Her friend and hairstylist, Ryan Randall, does the honor of pulling down her trousers for the camera.

Despite her trim figure, Osbourne has admitted she struggles with maintaining her weight. “I always cheat,” Osbourne told the Huffington Post.

She told Shape that she’ll have her fattiest meals in the morning: “If I’m craving pizza, I’ll have it for breakfast, salad for lunch, and oatmeal for dinner.”