Correct

狐狸尾巴

/ hú li wěi ba /
Strokes
https://i.cchatty2.com/filters:format(webp)/fit-in/684x0/img/202102/狐狸尾巴-Chinese-idioms-Cchatty-9815e35e-4aa7-4bdc-84bd-69c67daec174-1612777715.jpg

Collocation

1
揪出狐狸尾巴
2
抓住狐狸尾巴
3
露出了狐狸尾巴
4
狐狸尾巴露出来了

Definition

狐狸尾巴

Literally means:

fox's tail

Actually means:

something that gives away a person's real character or evil intentions

According to ancient Chinese legend,foxes cannot conceal their tails after turning into human being. Then fox's tail is used figuratively to connote that evil intentions, ill conducts or traces of ill conducts can not be concealed. Derogatory.

据中国古代传说,狐狸变成人以后尾巴藏不住。后来就用狐狸尾巴比喻掩盖不住的坏心眼、坏行为,或干坏事留下的痕迹。具有贬义色彩。

Example

Used as object or subjec (作宾语、主语)
1
guǎn
不管
fànzuìfèn
犯罪分子
zěnme
怎么
jiǎohuá
狡猾
  
,
de
liwěiba
狐狸尾巴
zǒnghuì
总会
chūlái
出来
de
  

No matter how cunning the criminal is, his fox tail will always come out.

2
Lái
  
,
jiě
大姐
bāng
jiū
chū
wánměi
完美
xíngxiàng
形象
bèihòu
背后
de
liwěiba
狐狸尾巴
  
,
kàn
qīngchu
清楚
shì
shì
zhēn
xiǎng
yào
de
nánrén
男人
  

Come on, big sister help you get out the fox tail behind his perfect image and see if he's the man you really want.

3
Fànmǒu
范某
wéi
以为
cōngming
聪明
  
,
wànwàn
万万
méiyǒu
没有
xiǎngdào
想到
ràng
chū
露出
liwěiba
狐狸尾巴
de
jìngshì
竟是
de
zhùzhái
住宅
diànhuà
电话
qīngdān
清单
  

Fan thought he was clever, but he didn't think it was his list of residential phones that made him reveal his fox's tail.