Mom's wild train ride, I'll jack off till she notices

A woman in a train compartment lies on a bunk, reading, then shifts to expose her underwear as a hand reaches under. Later, she's seen lying back, eyes closed, while a man's cock enters her from below. The scene cuts to a close-up of penetration, then to her face as she looks up, dazed. The final shot shows her bent over the bunk, hips raised, as the act continues. The setting is clearly a train sleeper car with narrow bunks and overhead storage.