In an exclusive interview with PEOPLE, the Queen of Christmas also opens up about whether she has plans for future Christmas shows

Mariah Carey had a lot of “fun” seeing Rihanna at her final Christmas Time tour concert.

On Tuesday, Dec. 17, the pop icon, 55, wrapped up her Christmas Time tour with a star-studded crowd that included the Fenty founder, 36.

When it came for “Always Be My Baby” during Carey’s set, she left the stage and went into the audience to greet fans and take selfies. But just as she was walking up the stairs back onto the stage, a security guard spoke to her, and she once again descended back into the crowd.

“I was like, ‘You cannot call me a diva again because I’m literally backing down the stairs,’” Carey tells PEOPLE of the moment during the concert.

As it turns out, she was heading back to the pit to see none other than Rihanna, who ended up getting her breast signed by the singer.

“That was hilarious,” Carey tells PEOPLE of the interaction over the phone from Aspen. “I had heard that Rihanna was coming to the show, but I didn’t think she was going to be in the actual crowd. She was fun.”

The “We Belong Together” performer also discussed whether or not she’s “sick of” Christmas music yet. (Spoiler: she’s not.)

“I’m in Aspen, and right now ‘Oh, Santa’ is playing over the speakers, and I’m like, ‘I guess I’m not sick of it,’” she says.