The phenomenon was the brain- child of chums Reid Mihalko, 36, and Marcia Baczynski, 26, who claim to have held the first formal cuddle party in New York City in the spring. They say they've staged about 40 since in cities including Washington, D.C., Las Vegas and L.A. The inspiration, says Mihalko (a New York City bartender and amateur masseur), came from his own life: "I would get together with massage-therapist friends and trade massages once a month. My friends who didn't do massage were jealous, and I jokingly told them we could have a cuddle party." One with its own peculiar etiquette, Web site (www.cuddleparty.com) and ambience: Music is mellow, stuffed animals are permitted but fooling around isn't, and snacks are kid-faves like Oreos. "Cuddle monsters" (Mihalko's words) like law student Bonnie Harris, 28, are coming back for more. "I feel safe because there are boundaries," says Harris, who has cuddled in Las Vegas and L.A. "And it's nice to get to know some-body lying down."