The daytime talk show co-host called out The Real Housewives of New York City star after she said Hostin had been "taking some drugs," in an argument that started with Hostin claiming Frankel yelled at one of her kids.
Hostin tweeted on Thursday: "Not surprising that a Reality TV personality who yells and bullies little kids on a beach lies. But I have witnesses [Bethenny]. [Regina Jansen] feel free to weigh in. #receipts Oh and @Bethenny – defamation ain't cute….."
Earlier Thursday, Frankel made an appearance on Watch What Happens Live with Andy Cohen, and a viewer asked the reality star about Hostin's claim that Frankel had once yelled at her child on a beach.
Hostin mentioned the story several times, including on June 13's episode of the daytime talk show, Page Six reported.
"I don't know," Frankel told Cohen on Thursday. "I think she's been drinking or taking some drugs. I don't know her!"
Frankel offered no basis for her speculation about drug or alcohol abuse, and it was not clear whether she was being literal or simply joking.
Hostin told the story of her child's alleged encounter with Frankel at the beach on The View when the panel was discussing a breakdown the Skinnygirl mogul had during a Miami girls trip on RHONY.
"I don't know Bethenny, but I have seen her behave like that on the beach," Hostin claimed. "I have seen that kind of behavior when Bethenny yelled at my child at the beach."
"It was in the middle of the day, and my child was about 7, playing with other children at about 2 o'clock in the afternoon, and she said that her child was napping inside with the window open and that our children were being too loud on the beach," Hostin continued, referencing Frankel's 9-year-old daughter, Bryn. "She yelled at my child, and I went out there and stood in front of my child, and I yelled at her and told her that adults speak to adults. And she knows I'm telling the truth."
A source close to Frankel spoke to PEOPLE about the claims, saying it was not true.0comments
"Bethenny doesn't even know her. It seems so strange that Sunny has such a fixation on her," they told the outlet. "Sunny spoke negatively about Bethenny during her Puerto Rico efforts and she continues to do so. Not sure what her issue is."
The Real Housewives of Beverly Hills airs Thursdays at 9 p.m. ET on Bravo. Watch What Happens Live with Andy Cohen airs Sundays through Thursdays at 10 p.m. on Bravo. The View airs weekdays at 11 a.m. ET on ABC.