Similar, but not the same.
In Chinese mythology, fox demons are always female. They dress up as beautiful woman to seduce man, then eat them or take their souls.
But sometimes when they are drunk or too happy or sth, they might be careless and show their tales. Then everybody will know the truth.
So, 狐狸尾巴露出来了 means someone wants to do something bad but failed to hide his/her intention.