My dad was a bank manager, and one day he got worried about us being leveraged to get him to steal money. Since both my granddads were dead, we agreed on “Is Grandpa okay?” as a phrase to suggest we were trouble.
A few months later, I decided to try it out. When he called from a bank, I dropped in a question about my granddad. “What do you mean?” He said. “He’s been dead for years.” The good news is that we never needed to use the phrase for real.