The bus lurches, adding thrill as the older man, his eyes gleaming with lust, turns the younger man around, lifting his shirt to expose his smooth back. He spits on his hand, lubing up the younger man's tight hole. The younger man, now rock hard, presses back, eager. The older man enters him slowly, then picks up speed, his hips slapping against the younger man's ass. The younger man bites his lip to keep quiet, his own cock aching for release. The older man comes first, filling the younger man, who follows suit, his cum dripping onto the bus floor. They clean up, exchange knowing smiles, and exit at the next stop, leaving the bus filled with their secret.