“Are you kidding me?” Dennis, 27, said in a video shared on good friend and costar Danni Bird’s Instagram Story on Wednesday evening.
The mother of two’s reaction was shared hours after Jacobs posted an emotional note on Instagram to publicly apologize to Dennis and Southern Charm fans for things she said on the hit Bravo show.
As fans know, Jacobs and Dennis have had a tense relationship — their feud playing out on Southern Charm’s fifth season. At the time, Jacobs was dating Thomas Ravenel, Dennis’ ex and the father of her two children: daughter Kensie, 4, and 2½-year-old son Saint.
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In her letter, Jacobs wrote, “I’ve learned a tremendous lesson,” to which Dennis said: “This lesson? That’s a tremendous word for you!”
Dennis added, “Yours truly. Yours truly? She’s writing this to nobody! Are you kidding me?”
Jacobs apologized for her comments towards Dennis’ parenting, including referring to Dennis as an “egg donor,” saying her kids “weren’t planned on,” insulting her mothering, suggesting Dennis was on drugs, and claiming she sees Ravenel’s kids more than Dennis does.
“I crossed a line and hurt people who don’t deserve it,” Jacobs wrote, later adding, “I can’t rightfully describe how sorry I am, but I’d never forgive myself if I didn’t at least try.”
This isn’t the first time Jacobs has attempted to patch things up with Dennis since Southern Charm’s cameras stopped filming.
In an exclusive interview with PEOPLE in July, Jacobs said she ran into Dennis at a restaurant, and hoped they could meet to reconcile their differences. “I actually asked her if she would ever want to get together and talk — coffee, lunch, my treat,” Jacobs recalled. “Kathryn said no.”
Last week, PEOPLE confirmed that Jacobs and Ravenel, 55, had split after more than a year of dating — each even deleting all traces of the other off their Instagram accounts.
She revealed the news on Aug. 15 in a teary Instagram live video, saying, “I love Thomas and I’ll always love Thomas. I’ll always care about him.”
“I made a lot of mistakes, and there are things that I just shouldn’t have said,” Jacobs shared. “I just should have kept my mouth shut. It was not my place. And I think the hardest thing is going to bed every night and thinking how different things would be in my life right now had I just shut my mouth. So I do. I beat myself up a lot.”