During a recent interview, the folks at Sirius XM's Cosmo Radio didn't think Justin Bieber could get his pal and "Baby" costar Ludacris on the phone. Not only did Justin call up the rapper, but the two dished on how they go way back -- and who gives who girl advice!
Watch Justin and Ludacris chat below:
What do you think of "Baby?" Who do you think Justin should collaborate with next on a song?
Photo: Maro Hagopian