Kathryn Dennis and Thomas Ravenel are returning to "Southern Charm" for season four -- and picking up right where they left off. After years of on and off dating, Dennis and Ravenel are very much off and when it comes to the custody of their children, and they appear to be in the midst of a full on war in a recently released sneak peek at the upcoming 4th season of the Bravo reality show.

On February 17, Radar Online shared a preview of the new episodes and noted that the custody battle between Dennis and Ravenel over their two children, daughter Kensington Calhoun and son Saint Julien, had taken a turn for the worse.

In the trailer, Ravenel is seen taking aim at Dennis after she reportedly refused to comply with a drug test — and told her friends about the issue at a party.

“Why won’t she go take a drug test?” he questioned a group. “[Kathryn Dennis] won’t go ’cause she knows she’ll fail.”

Meanwhile, after Ravenel was seen blasting his ex-girlfriend to her friends, she was seen crying. As the Radar Online report revealed, Dennis appeared to be distraught over being separated from her daughter while Ravenel continued to enjoy his social life, reportedly romancing their co-star Landon Clements, who Dennis feuded with heavily during season three, instead of working on their co-parenting relationship.

Kathryn Dennis and her ex-boyfriend continue to feud online

According to the report, Kathryn Dennis and Thomas Ravenel have remained locked in a bitter battle with one another since filming the 4th season of "Southern Charm" and just days ago, they were reportedly involved in a Twitter feud. As for when the estranged couple last saw their children, the outlet noted that Dennis had last shared a photo of herself and her daughter, Kensington, on social media over one week ago while Ravenel shared a picture of himself and his kids just last week.

To see more of Kathryn Dennis, Thomas Ravenel and their family, tune into the season four premiere of "Southern Charm" on April 3 on Bravo TV.