We love it when our favorite celebrity kids get together for a playdate!

Before Mariah Carey's annual Beacon Theatre Christmas show on Monday night, Beyoncé's daughter Blue Ivy Carter met the "All I Want for Christmas Is You" singer's twins, Moroccan and Monroe.

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"Backstage at Christmas time with our beautiful children. @beyonce #christmas #family #love," Mariah captioned an Instagram photo of the group.

She also snagged a solo shot with Bey, writing, "I love you @beyonce thank you sooooo much for coming out tonight!"

Scroll down to see more photos of Beyoncé and Blue Ivy living it up!