Idiom
keep something to oneself
Theme: SECRECY
to keep something a secret. (Notice the use of but in the examples.)I'm quitting my job, but please keep that to yourself.Keep it to yourself, but I'm quitting my job.John is always gossiping. He can't keep anything to himself
Idiom
keep something tokeep (something) to (yourself)
to not tell anyone something.He kept his business completely to himself, and even his wife didn't know he was a spy all those years.