There’s an unspoken rule around the world that passengers on public transportation don’t talk. If someone starts singing or talking to themselves, passengers just ignore them. But no one could ignore the scene that erupted on one British subway car last weekend. One, then two, then many more ‘passengers,’ who were really Adam Street Singers, started singing romantic song, until the climax when a man appeared and asked his girlfriend to marry him. The video is featured on YouTubeTrends