Just ask Kim Zolciak: Things are not always what they seem.

On Friday, the “Don’t Be Tardy” star posted a sexy selfie to Instagram in a black bikini. “So many comments asking about my bathing suit,” she captioned the image, which showed off her taut tummy and ample cleavage. “Also about my diet …”

The mom of six continued, taking the opportunity to shill for 310 Nutrition, a shake meal replacement, but assuring followers that “you can definitely pinch an inch or 5 for that matter but I love to live and I love to eat.”

But come Saturday, paparazzi snapshots of the 37-year-old presented a very different image. The candid snapshots showed Zolciak — with her signature red Solo cup in hand — walking along a Cancun beach wearing a black and gold string bikini, looking unlike the image she posted the day prior.

On Sunday, Zolciak fired back at reports that claimed she’d altered the image posted Friday, showing off her stomach on video.

“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 began the explicit Instagram video, which co-starred daughters Brielle, 18, and Ariana, 14. “I’m not a bulls—–r, I don’t have to f—-ing bulls–t so f—k you.”

Zolciak was in Cancun to celebrate her fourth wedding anniversary with her husband, NFL player Kroy Biermann.

Just last month Zolciak, who suffered a mini-stroke in late September, underwent heart surgery, forcing her to withdraw from the current season of “Dancing with the Stars” after doctors discovered a small hole in her heart.

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