OK! Exclusive: Ramona Singer’s ‘Nasty To The Core' Behavior Forces Dorinda Medley’s Boyfriend To Kick Her Out Of His Party

It may have been turtle time for Ramona Singer when she attended Dorinda Medley’s boyfriend John Mahdessian’s party, but not for the “shocked” guests and staff! The Real Housewives of New York star’s “nasty” behavior forced her to be thrown out of the December 8th soirée.

“She was really demanding with the bartenders,” an eyewitness exclusively told OKMagazine.com. “She went to one end of the bar and said, ‘If you don’t have a vodka martini in my hand by the time I get to the end of the bar I will cause a fit and have you guys fired!’”

The Singer stinger attended the party, which celebrated the new window display of Mahdessian’s high-end dry cleaning and restoration business Madame Paulette, with a “much younger” plus one. “Her date was stumbling and he fell over and knocked over one of the displays,” the onlooker said of the "intoxicated" mystery man, who reportedly dated LuAnn de Lesseps. “He started screaming at the bartenders for not serving him: ‘Who do you think you are! I rule this town!’”

Singer even got rowdy with the staff of Aneu Catering Company when she “stuck her finger” in an employee’s face for their refusal to serve the couple. “She came at the employees demanding drinks for this person who was obviously intoxicated and causing a scene,” a second eyewitness revealed. “She offended everyone. People were standing there with their mouths open because she was screaming and yelling at anybody that got in her path.”

The RHONY star’s vow to change her drama-starting ways after her split from cheating husband Mario Singer could’ve been an act for the cameras. “She’s inauthentic to viewers,” the source said. “You feel sorry for her on TV, but when you meet her in person she’s nasty to the core. She was nastier than I’ve ever seen her.”