Mariah Carey's 13 million twitter followers know what she and husband Nick Cannon did to celebrate his 33rd birthday Tuesday night!

The singer sent a message to her husband via the social network on Tuesday to let the America's Got Talent host know what was in store for him when he got home from work-- boobs!

Wearing an unbuttoned white shirt with a black lace bra underneath Mariah posted the sexy selfie, a close-up shot of her cleavage, on Twitter.

"Happy Birthday to my Hubby @NickCannon..."my baby I'm waiting on youuuu"hahaha! KKLB! GHL!!!! Mwah !!!!!" she wrote.

Nick and Mariah have been happily married for five years now. They met on the set of her "Bye Bye" music video and were married in 2008. They have two children, twins Moroccan and Monroe, born in April 2011.