I've never had any real emergencies, but I carry an emergency key at all times just in case. It's in a small envelope with my husband's signature across the seal.
There was one occasion, a very long time ago, when he forgot the key during a weekend getaway. I wasn't as obedient back then as I am now, and every time he suggested I take out the emergency key I pointed out that I was just fine and wasn't experiencing any emergencies.
Eventually he took it out of my purse and tore it open himself.
I probably deserved a severe punishment, but I think he let it slide because we were on vacation.
And he never forgot the key again!