出处：按学科分类—语言、文字 中国对外翻译出版公司《汉英成语词典》第255页（228字）
比喻不自觉地透露出自己的坏主意，例谁也没有问他，他却赶紧站起来为偷窃的事辩白，分明是不打自招。
No one had asked him to explain how the theft happened but he stood up quickly and did so．Clearly it was an unsolicited confession