Stripped down to her skivvies, Kim Zolciak bared her bottom on Instagram Monday ahead of a spa procedure that would freeze her most notable asset.

“Venus Freeze at Magnolia Med Spa this morning! Gotta keep my s–t tight! #BeachBoundTomorrow #LastWekBeforeIStartFilming #StarbucksInHandOfCourse,” the reality star scribed.

While Zolciak, 37, is no stranger to flaunting her bum both on-screen and off, the “Don’t Be Tardy” star has come under fire for allegedly doctoring her social media snaps. It that hasn’t stopped the mom of six from showing off her svelte physique and Zolciak took aim at several gossip sites in November for releasing photographs that painted her bikini bod in a different light.

“So, um, I just have to comment again on how much the Daily Mail and TMZ are full of s–t and just show you guys what I really look like,” Zolciak ranted on Instagram at the time. “I’m not a bulls—–r, I don’t have to f–king bulls–t so f–k you.”

Zolciak shared a series of swimsuit shots while vacationing with her family last month. In one photo, husband Kroy Biermann can hardly keep his hands off the busty blond as she soaked up the sun in a shimmery green two-piece.

This article originally appeared in the New York Post's Page Six.