The metro car rumbles, echoing the beat of the stranger's heart as the black vixen devours his cock. Her eyes never leave his, even as she takes him to the hilt, her throat constricting around his sensitive tip. She moans, the vibration sending waves of pleasure through him. He grips her hair, guiding her head as she bobs, her tongue flicking against his shaft. The train screeches to a halt, and they freeze, her lips stretched wide around him. As the doors open and close, they remain locked, her mouth full, his cock pulsing, their secret sin hidden in plain sight.