I first became aware of this song when I heard Bryan Batt sing this at Seth's Sirius Show (at the Times Square Visitors Center). I enjoyed listening to this in the audience on June 16, 2010. https://www.youtube.com/watch?v=-uhpyQst780
"Noel [Coward] and I were in Paris once. Adjoining rooms, of course. One night, I felt mischievous, so I knocked on Noel's door, and he asked, 'Who is it?' I lowered my voice and said 'Hotel detective. Have you got a gentleman in your room?' He answered, 'Just a minute, I'll ask him.'" (Beatrice Lillie)