Tree Hole - for secrets

[tree123]

I wonder whether there's an English word or phrase which refers to someone can tell their secrets or privacy safely.

In Chinese, the phrase tree hole is used. Does this make sense in English?

 

[abaka]

The literary word is confidant(e).

You can also call someone you really trust a bosom buddy, but that has a rather masculine connotation.

 

[Rover_KE]

I wonder whether there's an English word or phrase which refers to someone we can tell our secrets to in confidence.

In Chinese, the phrase "tree hole" is used. Does this make sense in English?

No.