The metro's rumble vibrates through them, echoing the pulsating need between their legs. She unbuttons her blouse, revealing her heaving, creamy mounds. He groans, palming her flesh, his thumbs brushing her hardening nipples. She unzips him, freeing his stiff, veined cock. She moans, "Fuck, it's huge!" as she guides it between her breasts, titty-fucking him with wild abandon. The train's jolt sends him over the edge, and he spurts hot cum onto her chest, marking her as his in the crowded, oblivious metro.