In the pulsating heart of Madrid, the metro's rhythm.matches that of the anonymous lovers' hearts. A man in a crisp suit, his tie loosened, stands behind a woman in a fitted skirt, her blouse slightly unbuttoned. The train lurches, pushing them together. He feels her warmth, her breath hitches as his hardness presses against her. She leans back, her head resting on his shoulder, her body language inviting. He takes the hint, his hand slipping under her skirt, his fingers finding her wetness, stroking her expertly. She grinds against him, her quiet moans lost in the train's rumble. The train slows, they separate, but the intense connection lingers, unbroken, until the next stop.