Justin Bieber Embroiled in Ugly Spat with Ex-Mentor Usher at Oscars After Party — Amid Claims 'Baby' Singer Wants to 'Freeze Out People from His Past'

Justin Bieber and Usher were involved in a 'heated exchange' at post-Oscars party, sparked by the 'Burn' singer confronting his ex-protege with 'energy and anger.'