October 27, 2005 -- THERE'S no love lost between fashionable Italian "it girls" Margherita Missoni, 22, and Francesca Versace, 21. That's because Francesca, niece of Donatella Versace, was dating 22-year-old Ernst August, son of Germany's most high-profile aristocrat, Prince Ernst of Hanover, when Margherita, of the rival Missoni fashion dynasty, managed to steal him away from Francesca last summer. And supposedly it wasn't the first time Missoni had beguiled a boyfriend of Francesca's. "It happened once before with another guy, too," clucks our source. "They really hate each other. The last time they were both in New York, they couldn't even look at each other."