The rumble of the metro serves as the soundtrack to their passionate encounter. The redhead unbuttons her blouse, revealing her lacy bra. The brunette leans down, taking a nipple into her mouth, causing the redhead to gasp. Their hands roam, fingers dipping into wet crevices, eliciting moans that blend with the rhythmic clacking of the train on the tracks. The brunette, desperate for more, hikes up her dress, straddling the redhead, grinding her hips against her lover's thigh. The redhead responds, her fingers plunging into the brunette's eager pussy, as they both chase their release, their bodies moving in sync with the train's movement, until they're left panting and sated, their secret tryst hidden from the world above.