He realized that he had given himself away.他意识到自己露馅了。

　动词词组give sb./oneself away，意思是“暴露了自己（的真实情况或身份）；出卖了”（to reveal sb./oneself intentionally or without meaning to; to betray sb）
　　例句：
　　Your American accent gave you away. 你的美国口音让你露了馅。
　　He would never allow his family to give his friends away to the Nazis.
　　他决不让家人向纳粹分子出卖朋友们。