The city's heartbeat throbs around them as they explore each other's forbidden zones, fingers delving deep, tasting, licking, sucking, their bodies pressed tightly together in the crowded car, oblivious to the world around them. The busty one straddles her friend, impaling herself on that thick, black cock, riding it hard as the train rocks them, their grunts and moans drowned out by the city's hum.