Perhaps he should start fining them if they continued to leave the door unlocked.

They went for long walks, marvelled at the turquoise colour of the sea and enjoyed being able to leave their front door unlocked at night.

You can leave your front door unlocked when you go out.

It’s like investing in fingerprint identification for your front door and leaving your back door unlocked.

She will remind you if you have left the front door unlocked.