Rome: Singer Mariah Carey held a costume party where all her guests dressed as her. The “Without you” hitmaker threw a party at a villa in Lake Como, Italy where she was joined by 40 close friends, who all channelled their inner Carey, reports pagesix.com. "Even the men dressed like Mariah. But Mariah went as her alter-ego, Bianca, and spotted a jet-black wig," a source said. The 46-year-old singer was filming the party for her upcoming television series, reports femalefirst.co.uk.