Carlos Aured – La frígida y la viciosa (1981)
Carlos Aured directed this sex film about a wife who is frigid. The husband hits upon a novel solution, tie all 4 of her limbs to the bedposts and rape her! Gee, it was so simple. Before you know it, even her girlfriend ties her up and has sex with her. Then things get real kinky in yet another example of prime Spanish sexploitation.