Southern Charm star Kathryn Dennis gave birth to her second child less than six months ago, but looking at her bikini body, you wouldn't know it!

On Sunday, Dennis shared a photo of her post-baby body on Instagram, and in the caption of the photo, she revealed the motivation behind her weight loss.

"FIRST time in a swimsuit since my second born child and I have to say it -- I'm so proud of myself!" Dennis wrote in the caption of her photo.

Dennis went on to hint that it was her painful breakup from Thomas Ravenel, the father of her two children, which prompted her to get back into shape in record time.

"My body has essentially gone through a complete shock! 2 babies in 2 years at 24! Phew," she continued. "God definitely gave me the determination and strength to get the toxicity out of my life and finally get my body back I even threw on a fur coat because 1. It's by Mary Kate and Ashley (@elizandjames) and I love every single movie they've ever made because hello DUH and 2. I'm feeling sassy and finally realize that the people who have hurt me, well in the end, they've really only hurt themselves."

While Dennis and Ravenel made a habit of breaking up and making up for the last few years, their latest split appears to be their last.

"I know I've said that a lot, but we are definitely, officially, over," Dennis told The Daily Dish in April. "Taylor Swift said it: 'We're never, ever, ever getting back together.'"

"It was a long time coming. I think what really motivated it was that I had Julien in November, and I had hoped that having two children, something would fall into place somehow, magically," Dennis explained. "[Thomas] was talking about marriage in the hospital. He really wanted to make it work. And then he just flipped a switch, changed, and I don't know. I kind of was just realizing my kids were more important than the way I feel about him romantically."

For more Kathryn Dennis, tune into Southern Charm season three on Mondays at 9 p.m. on Bravo, and check out a sneak peek of tonight's new episode below.

Tags: kathryn dennis thomas ravenel southern charm Bravo Reality TV