Southern Charm : Kathryn Dennis Admits to Sleeping with Costar and Producer Whitney Sudler-Smith

Love is in the Charleston air.

On this week’s episode of Southern Charm, Kathryn Dennis admits to sleeping with castmate Whitney Sudler-Smith before the start of the season.

After murmurs of the possible hookup surfaced during a dinner party last week, Dennis finally fesses up to it while talking to her friends at Chelsea Meissner’s housewarming party.

“Our little darling Kathryn and our friend Whitney had a little rendezvous,” says Cameran Eubanks after Dennis asks the group for the “gossip.”

And Dennis doesn’t deny it.

“I swore to him [I wouldn’t tell]” she says before confirming it happened when they were both in Los Angeles.”

While dating a castmate is not unheard of (see: Meissner and Austen Kroll), this was a particularly shocking revelation given Dennis and Sudler-Smith’s past.

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Fans may recall that the two secretly hooked up before Dennis started dating her ex Thomas Ravenel, with whom she now shares two children. And while they both promised to keep their one-night-stand a secret, Sudler-Smith eventually told Ravenel, leaving Dennis caught in lie.

“The first time Whitney and I hooked up he said ‘Don’t tell anyone,’ and I was really intimidated by him at the time so I was like, ‘Okay, I really, really won’t,’ ” she says. “But at the end of the day, he’s the one that ended up telling everyone. I even lied to Thomas and at that point I was idiotically in love with him.”

To make matter worse, Dennis later accused Sudler-Smith, who is also a producer on the show, of being a bad influence on Ravenel while she was pregnant with their daughter Kensie, now 5.

And while Dennis and Sudler-Smith certainly seem to have repaired their friendship, the reality star doesn’t feel bad about spilling the beans.

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“Now I don’t give a s—,” she says. “If I was him I’d be like, ‘Yeah man, I sure did. ‘ “

So how was their night together?

“It wasn’t bad!” says Dennis.

The next day, Kroll and Craig Conover do their best to get Sudler-Smith to open up about the hookup as well, but they don’t succeed.

“F— you,” Sudler-Smith jokes before quickly changing the subject.

Dennis is now dating country singer Hunter Price. The two have been together since January.

Southern Charm airs Wednesdays (8 p.m. ET) on Bravo.