"My [heart emoji] Sinn just can't stand it! He has to be in every pic!!" she captioned a picture of Sinn photobombing a photo of her and husband Kroy Biermann sporting swimsuits and posing on the beach.
On another photo of her getting up close and personal with the adorable canine, Zolciak-Biermann wrote, "Best thing we ever did was rescue Sinn!! @cheftraceybloom rescued him and his 8 siblings and mom when they were 3 weeks old THANK God."
The former Dancing with the Stars contestant also posted a pic with her daughter Brielle and Sinn, using just the bikini, ocean and dog emojis as a caption.
Zolciak-Biermann is no stranger to posting bikini pics on Instagram: After cyberbullies criticized her appearance on the social media site earlier this year, the Don't Be Tardy star posted even more revealing pictures and addressed the mean commenters directly.
"I'm so f------ over all you bullying trolls!" she wrote. "I don't want your negative energy on my page, I don't want to share any part of my incredible life. You are jealous and it's a disease."