It means you Don't. Say. Anything.

Let's have a conversation about secrets.
Secrets are important. And when you're invited to be a holder of one, it's a privilege. And when you share it, or brag about having it, or spoil it for the official secret holders, it's a betrayal. Seriously, there's no other word for it. There's no one worse than the person who knows the secret peripherally, and then tells the secret.
Actually, you know what does make that person worse? Facebook.
Facebook makes every secret harder to keep, and makes every secret holder a liability, because the bad secret holders who can't and don't want the secret to be a secret will spoil it. And the peripheral secret holders who want to be the Secret Tellers are the worst. They will make little comments here and there. They will be "cute" or "subtle." They will make jokes.
Here I am, a peripheral secret holder who can keep a secret. And I've got Facebook. And I see that a couple other peripheral secret holders are making comments, or being "cute," in a way that exposes the secret in not at all subtle ways ... on the actual secret holders' Facebook pages. This is rude, and mean, and insensitive, and just all kinds of blabbermouthy. I feel so bad, because due to these peripherals who can't keep their mouths shut and their fingers unengaged on Facebook, the actual secret holders had to share their secret before they were ready to do so. And I think that's horrible.
On the up side, the actual secret holders now know exactly who they can and can't trust with their secrets in the future. And I know better now, too.
Secrets are important. The ability to keep them is even more so.