Chrissy Teigen and Ludacris put hours of rehearsals in before they hosted. This image appears in the gallery:All The Photos You Need To See From Inside The 2015 Billboard Music Awards 26. Chrissy Teigen and Ludacris put hours of rehearsals in before they hosted. Picture: Instagram 28 images See the full gallery: All The Photos You Need To See From Inside The 2015 Billboard Music Awards