Brothers Enemy

What level of hatred can a brother have over his own blood brother to spite him and pull him down at every little chance he gets? Why were Bruno's half-brother and his mum the Queen nursing deep hatred for his own brother by going as far as accusing him n the most important day of his life? It's all confusing but the point at which Tonia and her family aren't giving him space for an explanation was even broken as he was left to lick his wound......... What could be the problem? Let's find out from the movie.