The singer dedicated her hit song "Hero" to her billionaire beau James Packer, while performing at the Colosseum at Caesars Palace on Wednesday night.
Carey told audience members, "I've got a new heart."
"James is in the house," Carey revealed to the Las Vegas crowd before launching into the tune.
A source close to the couple previously told PEOPLE that Carey and Packer "are enjoying spending time with each other" and judging by Wednesday's concert, the pair appear to be going strong.
Just last month, the songstress and her Australian boyfriend were spotted packing on PDA in Portofino, Italy, before jetting off to Israel with Carey's 4-year-old twins, Moroccan and Monroe, her children with ex-husband Nick Cannon.