Unfortunately we couldn't find time to work on this project and won't before the deadline…  A pity, since the setup we imagined was pretty simple :

- a container to be fixed with suckers on the door ;

- a switch activated when the door opens ;

- an SD card containing WAV prerecorded sensual sounds and messages from a Isaac Hayes like voice ;

- a loud speaker ;

- an Arduino-like.

Each time the switch is activated, a counter is increased and a WAV file is played depending on this counter — the upper the counter, the happier the door.  The counter is decreased slowly with time — no opening, sadness coming.

Currently we only have the Arduino-like (YABBAS) and an empty SD card, so I guess we withdraw from the contest.