Oh god, have I ever seen a more tedious “erotic” movie than this one? I think not. On the eve of his wedding to the beautiful, young, otherwise untouchable aristocrat Hermangarde (Roxanne Mesquida), the “libertine” Ryno de Marigny (Fu’ad Ait Aatou) is cornered into justifying his sex life to his intended’s grandmother, which would probably be less icky in a movie that attempted to create a sense of the era in which it is set. But writer-director Catherine Breillat (Sex Is Comedy), adapting the controversial 1851 novel by Jules Barbey d’Aurevilly, seems more intent on ensuring that we understand how “hot” Ryno’s relationship has been with Vellini (Asia Argento), his Spanish mistress. (The film’s — and the novel’s — title in French? Une vieille maîtresse, or “an eldery mistress.” She’s 36.) Argento, of course, is the Italian actress best known for her near-exploitive work in horror films (George A. Romero’s Land of the Dead is a mild example), and she’s not capable of conveying Vellini’s impossible situation — as a woman forever cut off from true social acceptability — with any pathos. Or perhaps it was Breillat’s intention that her putative heroine be a moping, moaning, unsympathetic creature, because certainly her hero, Ryno, is no better. And there’s nothing more dull than watching two thoughtlessly cruel monsters having sex onscreen.