I'm single (not by choice) and always go alone to see a show. from RC in Austin, Texas (in NYC from June 7-10, 2013 and seeing: Chicago, Pippin, Vanya-Sonia-Masha and Spike, The Nance).
"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)