Where Do You Store Your Key?

This is primarily for KH’s, though anyone else can chime in: How do you store your keys? Is there a spare key available to him if an emergency arises? I plan on carrying one with me. Even though I dislike the thought of leaving one accessible to him, life happens and it seems wise to keep another at home just in case something serious occurs. Do you conceal a key around the house? Are you confident he won’t use it when he’s out? I’ve seen posts from men who locate their keys and act up. I definitely don’t want that option open to him, so covering all my bases is crucial for me. I’ve also read about some KH’s using a ribbon or similar marker to indicate if anything has been tampered with. This confuses me because I’m not sure exactly how it guarantees anything. Thank you in advance for your input! -BK