The 36-year-old TV and radio personality was asked the "60 degree question" of "What's the most diva thing that you've ever seen Mariah do?"
"Have twins," Cannon replied, joking, "She shut the whole hospital down."
"When they was born, she made me play her music as they was coming out," he continued. "It was a fantasy. They was dancing...to "Fantasy."
Cannon and Carey share twins Monroe and Moroccan, who will turn 6 this weekend on what would have been the former couple's ninth anniversary.
Cannon has told the birth story before.
"Now my wife wanted to make sure that when the babies came out, that they came out not only to a Mariah Carey song, but a live performance from Mariah Carey—her Madison Square performance of 'Fantasy'—so they came out to a round of applause," he told Gayle King in 2011.