OOPPSS!!

I noticed Ricki looking a bit furtive about what she had in her school bag. I checked, and it was something that in actuality I allow. Then I noticed:
The key to the front door was missing.

Sometimes Ricki takes the key out of the front door, planning to place “contraband” outside so that I won’t notice. However, to have the door locked without the key being there is DANGEROUS, as leaving the apartment in case of an emergency could be held up by searching for a key.
Certain that Ricki had taken the key, I started grilling her, and got nowhere. Finally I put a spare in the lock, and we went to sleep.
Several hours later I heard Ricki’s married sister entering. She and her husband are temporarily living in a room on our roof, and I had not noticed that she had gone out…. Taking the key with her.

In the morning, first thing I did was apologize to Ricki. But I feel bad about the mistake…..