It’s the #1 Christmas song this year (and every year) and now it’s a family affair. Mariah Carey is training the twins for backup vocals on “All I Want For Christmas Is You”!

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Roc & Roe have been practicing the background vocals to "All I Want For Christmas Is You", we're gonna take this one step at a time – we're very excited about it! It's our first video doing this! It's festive, Cmon!! 🎄🎶🎄🎶💖

A post shared by Mariah Carey (@mariahcarey) on Nov 28, 2018 at 3:56pm PST