Things are getting nasty on The Real Housewives of New York City.

In a clip from Thursday's all-new episode, LuAnn de Lesseps, 46, sits down with costar Ramona Singer to figure out why the Pinot Grigio entrepreneur declined to appear in her music video.

"I'm very proud of you for doing it, but I have a daughter. I'm a role model," Singer, 54, explains. "I'm a mother and I raise my daughter differently than you."

Taking a sip of her coffee, de Lesseps asks, "What is that supposed to mean?"

"I spend a lot of time with her," Singer responds. "That's why she is the way she is. She's a great girl and I'm very lucky."

Annoyed by what Singer is implying, de Lesseps snipes: "It is amazing how she turned out, I can tell you that."

Oblivious to de Lesseps' backhanded compliment, Singer adds: "When you spend time with your child they turn out well."

The Real Housewives of New York City airs Thursday at 10 p.m. EST on Bravo.