In the dim light of the train's restroom, a lone figure leans against the wall, his hand working furiously at his engorged cock. The movement of the train rocks him gently, adding to the sensation as he brings himself closer to the edge. His breath hitches, his grip tightens, and with a final, shuddering thrust, he comes, his hot seed painting the cold, hard floor of the restroom. He cleans up quickly, zipping up and stepping back into the bustling train, his secret safely kept.