On Thursday's episode of The Real Housewives of New York City, the testy costars put their differences aside when Sonja Morgan, 47, surprises them with a belly dancing lesson during their Moroccan vacation.

"Welcome to the belly dancing den," she tells Ramona Singer, LuAnn de Lesseps, Jill Zarin, Kelly Bensimon, Alex McCord and Cindy Barshop.

"If you got it, shake it, and even if you don't have it, shake it anyway," Singer, 54, advises the group. "Sometimes I wish these girls would loosen up and have some fun. Let's get in the spirit. And you know what? I can still shake it, I must admit."

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