The Magnificent Ambersons.

The spoiled rotten and utterly unlikable rich kid George Amberson becomes horrified when his recently widowed mother rekindles her relationship with the wealthy Eugene Morgan, who she left decades earlier in order to marry George's father. As George struggles to sabotage his mother's new romance, he must deal with his own romantic feelings for Morgan's daughter and the consequences of his meddling as his once great family falls into ruin due to his machinations...