Can I count on you?

我可以信任你吗？

Could you keep a secret?

你能保密吗？

Keep it to yourself.

你自己知道就行了。

This is for your ears only.

我只告诉你了哦。

Don't say I told you.

千万别说是我告诉你的。

This is not public knowledge.

这可不是谁都能知道的。

Just between you, me and the lamppost.

你知我知子知。