The HBO production of the Pulitzer Prize-winning play "Dinner With Friends" doesn't hit TV until Aug. 11, but last weekend there was a screening and dinner -- with friends -- in New York's posh Hamptons, reports PEOPLE. Stars of the film Andie MacDowell, Dennis Quaid and Greg Kinnear showed up -- fellow cast member Toni Collette was the only one missing -- as did "The Sopranos" star Aida Turturro and model Eva Hertzigova. Quaid, recently divorced from Meg Ryan, arrived with his new girlfriend, blonde actress Shanna Moakler; Kinnear arrived with his wife, Helen Labdon; and MacDowell, who last week announced that she's set to marry childhood chum Rhett Du Camp Hartzog, arrived by herself. The film concerns how a marital breakup of a couple affects the relationship of friends. During production of the project, though, it was the reverse that happened: MacDowell, 43, became involved with Hartzog. Not that this changed a thing, Kinnear, 38, claimed to PEOPLE. "It only just happened," he said of their relationship. "She always looks happy to me -- and gorgeous and beautiful."