In last week's episode, Singer, 63, wasn't happy with McSweeney's behavior at her birthday party when she noticed McSweeney's dress had slid up while dancing. And the OG housewife took her dissatisfaction a step further on Thursday night's episode when she began discussing McSweeney's mental health behind her back, saying that she shouldn't have had so much to drink at the party.
Watch TODAY All Day! Get the best news, information and inspiration from TODAY, all day long.
"I found out she's bipolar, and she's on medication," Singer told co-star Sonja Morgan during the episode. "And I know people who are bipolar, and you cannot mix alcohol with meds — it makes you act not responsible. It's actually very dangerous."
In a confessional interview, Morgan questioned the validity of Singer's statement, saying: "Why is Ramona telling me this, and where is she getting this information? Is it true even? I'm getting along well with Leah."
When several of the show's stars arrived in Cancun, Mexico, for a girls trip later in the episode, McSweeney, 37, told co-star Dorinda Medley that she was upset because Singer still wouldn't talk to her and had been gossiping about her mental health with others.
"Whatever, I don't care about the party," she said. "She's saying I showed my vagina to people, which is demeaning, but it's a lie, and it's weird that she's lying, whatever. But when you start talking about 'Leah has depression, she's on pills,' it's just a line you don't cross."
During the episode, McSweeney admitted that Morgan told her about the gossip and then took some time to explain the truth about her mental health struggles during a candid chat with Medley.
"I was diagnosed with bipolar II disorder on my 30th birthday and really dedicated the last seven years of my life to getting it under control and to getting myself in a good place," she said. "I'm not even on medication, so for her to be talking about it in this way is despicable."
When the two feuding ladies finally talked during dinner, McSweeney expressed her frustration with the situation.
"I really don't have that much to say for once in my life except that I'm really disappointed that you would talk about my depression issues behind my back as a way to belittle me when I've actually overcome all of them," she said.
After a bit of back-and-forth, Singer simply said, "You hurt me," and continued: "I took you in. If you don't get it, then I can't explain it to you."
Singer eventually stormed off, and McSweeney ended the conversation, saying, "I didn't do anything! She needs to stop talking about my vagina."
"The Real Housewives of New York" airs Thursday at 9 p.m. ET on Bravo!