I had planned everything. When this handsome young fisherman docked at the lighthouse to bring me my monthly supply of food and fuel, I discreetly untied the rope holding the boat to the quay. Even if my irresistible charm was to be enough to keep the boy for the night, you never know. 

With plenty of wine and - did I mention this? - my irresistible charm, we were both very excited, it was going to be a hot night.

The telephone rang. Several boats were complaining to the harbour master's office that the light beam was stuck, that there was a problem with the rotation mechanism, and... that I had to go and see what the fault was.

Reluctantly, I got up from my visitor's lap, climbed the stairs to the top of the lighthouse, opened the door to the outside platform and went to see what the problem was.

A strong gust of wind slammed the door shut. 

The keys were on the door, inside.