'What's it like to have my trousers pulled down?' Lawson asks. 'It's not as awful as it seems. Doing that kind of thing with an actress like Judith Paris, who pulls them down, is easy, because she is very professional about it. No, the really difficult moment is when she grabs me by the balls a few seconds later. It's much more telling, because you simply can't fake that. However, Judith was trained as a dancer, so her technique is, well, absolutely solid.'
Lawson earns his top billing: the entire night revolves around him - his dancing, his singing, his energy. Does the responsibility weigh heavily? 'Well, nerves come and go,' he says. 'You can do it for four or five months, and then suddenly dry.
'I haven't so much dried stone- dead as just got worried about what I am doing, mid-song. I have a couple of big solo numbers. They still worry me - I'm so exposed. When it's going out the window, I never look at the conductor. I just start panicking, get frightened, and concentrate like mad. It's probably got a lot to do with fatigue; doing this show eight times a week is very tiring.'
This performance was, he thinks, the best of the week - 'even though I was a bit jumpy before going on. But the audience responded fantastically, which makes all the difference. There was just one tricky moment, in my song 'A Pox on Love and Wenching'.' He takes a sip of Guinness and reflects on the moment.
'Usually, the line 'Since I was purged of the urge . . .' gets a big laugh; tonight it didn't. I normally leave a bit of a gap before the next line, which is '. . . to procreate'. But tonight, there was just silence, so I had to plough on through, and rely on the band to catch me up.
'Laughter is like surfing; it's like a wave coming out of the auditorium - before it has died off, you must come in with the next line. But if you come in too soon, no one will hear what you say.
'I still have nightmares about the show. They either take the form of forgetting my lines, or having to go on without my costume. The consistent factor is that no one ever helps.' He drains his Guinness. 'Normally, I go straight home, flaked out in the back of a car. I keep thinking about the show. I always think of it as work in progress.'