The 45-year-old singer started dating the Australian billionaire during the summer with the pair enjoying a luxury vacation on his super yacht and Mariah could not be happier.
Speaking at the Harper’s Bazaar ICONS issue party on Wednesday, Mariah told 'Entertainment Tonight': "It's fun, I'm not gonna lie. He's not joining me inside tonight, but we were together last night, so that was fun."
Mariah split from estranged husband Nick Cannon last summer after six years of marriage and it has been claimed that she and James, 48, are eager to tie the knot.
A source previously said: "James wants to marry her sooner rather than later, and she is very open to the idea."
And the couple are said to have already discussed having a child together, as Mariah, who has four-year-old twins Moroccan and Monroe with Nick, wants to have another baby with James, who has three children from previous relationships.
Another insider said: "Mariah feels that having a child with James would be a blessing from God.
"She wants another child and is telling friends she's not too old."
Mariah Carey Having 'Fun' Dating Boyfriend James Packer http://t.co/fDYOMoBr1A— Carla. #1ToInfinity (@MariahCareyPT) September 17, 2015