Mariah Carey shows cleavage at casino launch

Singer, Mariah Carey stunned in a plunging black gown to color coordinate with her Australian boyfriend's formal tuxedo as she performed her hit song "Hero" to commemorate the grand opening of his new Studio City resort in Macau, China.

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Carey, 45, and Packer, 48, celebrated the launch of the $3.2 billion Hollywood-themed casino resort together, less than one month after making their red carpet debut as a couple at The Intern premiere in New York City.

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Hollywood stars,  Martin Scorsese, Robert De Niro and Leonardo DiCaprio gathered at the 1600-room complex to premiere the 15-minute short film The Audition.