A raw, visceral masterpiece of prehistoric eroticism, cinematic concept art in the style of Frank Frazetta and Boris Vallejo. A dimly lit, cavernous grotto illuminated by the flickering, warm orange glow of a central fire pit, casting deep chiaroscuro shadows. In the foreground, a muscular Neanderthal male with matted hair and a thick beard, wearing a low-slung rough hide loincloth, gripping the hips of a lean, powerful cavewoman on all fours atop cured animal hides, explicit penetration, massive phallus, deep thrusting, intense primal exertion. The woman looks back over her shoulder with an expression of ecstatic pleasure, featuring enormous breasts, glistening skin coated in animal fat and sweat, and intricate tribal scarification. Background features multiple naked prehistoric couples engaged in various sexual acts on furs. Rough-hewn rock walls with primitive ochre cave paintings. Textures of damp earth, coarse fur, and sweat-slicked skin. Earthy color palette, deep amber, burnt sienna, charcoal grey, and raw skin tones. High contrast, dramatic lighting, painterly digital art, ultra-detailed anatomy, 8k resolution, volumetric smoke and embers.