Correct

露尾巴

/ lù wěiba / 
Strokes

Example

As a Verb

show one's tail―show one's true colours; give oneself away

1
Rìzi
日子
yī
一
jiǔ
久
jiù
就
lùchū
露出
húliwěiba
狐狸尾巴

reveal one's true colours as time goes by