That Most Important Thing: Love (1975)
That Most Important Thing: Love (original French title: L'important c'est d'aimer) is a French film directed by Polish filmmaker Andrzej Żuławski. It tells the story of a passionate love relationship between Nadine Chevalier, a B-List actress (Schneider) and Servais Mont, a photographer (Testi) in the violent and unforgiving French show biz.
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