ET's Katie Krause spoke with Cannon on Tuesday, where he shared the hilarious parenting story that might have both him and his 7-year-old son, Moroccan, on Carey's naughty list.
"I don't know if I'm supposed to say this, but my son, maybe like, 2 years ago, wrote a song," the 37-year-old rapper and actor teased. "He was turning 5, and he wrote a Christmas song and I was really excited."
"I told his mom like, 'Yo, he told me he wrote a Christmas song,' and she was like 'Yeah, have you heard it?' and I was like 'No, why?' ...she was like, 'Tell him to sing it for you next time,'" Cannon said.
What came next was a little more R-rated than Carey's usual holiday songs. "He goes, 'I saw your boobies on Christmas Eve, they were so beautiful, I didn't want to leave,'" he recalled. "I was like, 'That's my boy right there!'"
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"I was like, 'This is the best Christmas song I've ever heard in my life!'" Cannon continued, laughing. "No joke. And like, til this day, he sings it every Christmas!"
"Mariah is gonna kill me that I told you that," he joked.
In all seriousness, Cannon said that little Moroccan and Monroe actually have some musical talent. "They're always like, in my studio. Like, everywhere I go, I have a studio, whether it's the house, my office, there's always a studio," he explained. "My son loves to drum and my daughter does too, but she's more like, on the piano and stuff."
Carey also opened up about her twins' possibly following in her footsteps while chatting with ET last year. Watch below.