OSB on Justin Bieber Rocking Out to 'Baby Mama,' Hottest Celeb Baby Mama

D5 and Smokeone of L.A. rap duo OSB sat down with VladTV and spoke about how Big U formed the group, leading to their breakout single, "Baby Mama." They explained that the hit track was the first thing they recorded in the studio, and it was clear they were onto something.  Moving along, D5 and Smokeone spoke about watching Justin Bieber rock out to their song and how they'll be coming out with new projects in the near future. To hear more, including them rank their hottest baby mamas, hit the above clip.