Keep this to yourself

Keep this to yourself.

a phrase introducing something that is meant to be a secret. Andy: Keep this to yourself, but I'm going to Bora Bora on my vacation. Henry: Sounds great. Can I go too? John: Keep this to yourself. Mary and I are breaking up. Sue: I won't tell a soul.
See also: keep, this
References in periodicals archive ?
For Heaven's sake keep this to yourself, as the discovery of it may prove fatal to us, our numbers, sorry am I to say, being less than I had any conception of: but necessity, dire necessity, will, nay must, justify an attempt.
Whilst you may want to do the right thing by them, and keep this to yourself, you may feel torn, especially if you feel that their welfare would be better served by being more open.