Usher tells Justin Bieber: 'don't f**k up your success'

Usher has warned Justin Bieber not to "f**k up" his success.

The 'Scream' hitmaker - who mentored the 19-year-old singer alongside his manager Scooter Braun in 2007 - is seen giving his protégé a few words of advice in a teaser for new 3D film, 'Believe'.