Complex sentence: Throughout the film, Giovanni expresses a desire to talk about his life as a mobster (seemingly expressing some guilt, though he always claims this is untrue), and the debate after the film prompts him to tell his story to the audience.
Split into simpler sentences: Throughout the film, Giovanni expresses a desire to talk about his life as a mobster, seemingly expressing some guilt. The debate after the film prompts him to tell his story to the audience.