fourth wall
noun /ˌfɔːθ ˈwɔːl/
  /ˌfɔːrθ ˈwɔːl/
[singular]- the imaginary barrier that separates the characters in a work of fiction from the people who are watching or reading the story they are in第四壁:想象的屏障,将小说作品中的人物与正在观看或阅读其故事的人们区分开 - The actors break the fourth wall and talk directly to the audience.演员打破第四堵墙,直接和观众对话。 
 
- The actors break the fourth wall and talk directly to the audience.