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。