Watch Backstreet Boys Sing a Lullaby for Andy Cohen’s Baby

Andy Cohen is anticipating his first baby quickly, so Backstreet Boys determined to shock the Watch What Happens Live host by singing his unborn son a lullaby.

"We have a really particular deal with simply to your future child boy," AJ McLean says within the video under. "So that is from us to you."

The pop band then sings "Twinkle Twinkle Little Star" a cappella, full with good harmonies. McLean then joked that they need to put out a kids's album — though it does sound like an excellent thought.

Check out the video under, and take a look at to not be lulled to sleep.