I actually did this about 10 years ago in an office building. It was at lunch time, and I was nervous becasue the door to my office didn't have a lock. Someone could have come in unexpectedly, and someone in the building accross the street could have seen in. My office was at the end of a hallway, so if the door was opened, anyone in the hall could have seen inside.
Now my fantasies are less risky, but also less conventional.