Just before the great BoJo event in the conference hall in Birmingham, there was a kerfuffle in the crowd. The cameras swung round to film the audience and, following their lenses, I could see the object of their adoration. It was David Cameron, who had “slipped” into a seat to listen and was now watching himself being filmed, his preternaturally squeaky-clean face looking even more squeegeed than usual.

Boris Johnson got the full celebrity treatment, including that most coveted of things, a pre-speech film tribute, in which we saw Dave watching Boris win on election night. So now, in the hall, we had Dave watching Dave watching Boris. And soon, when Boris arrived, we had Boris watching Dave watching Boris. Sometimes at the Tories you feel as though you are in a PR masterclass and not at a political convention at all.

Boris shambled on, his jacket flapping like a tarp that has lost its moorings in an autumn gale. His navy-blue tie didn't match, his hair needed thatching. His appearance was met by an instant standing ovation - the four Tory boys in front of me jumped up to video him on their mobiles - and wolf whistles. Yes, wolf whistles. What is going on? I'm sure Dave, his smile now so fixed that I suspected Superglue, hated that.

“That's really an extremely fine reception,” mumbled Boris. “Much more generous, I must say, than in 2006, when I was physically pelted with pork pies.” Cue hysterical laughter. “Or last year, when my speaking style was criticised by no less an expert than Arnold Schwarzenegger.” By the time he said Arnold they were guffawing.

The stand-up comic (also, of course, the most powerful Tory in the land) continued his schtick. “It was a low moment, my friends, to have my rhetorical skills denounced by a monosyllabic Austrian cyborg.” Now they were howling. His next joke, about terminating Ken Livingstone, brought actual screams of laughter.

How they love him! The buffoon has grown up but not, I am happy to say, entirely. This was his most accomplished speech, but he still takes risks when he speaks, although he no longer allows things to descend into pure anarchy, and the crowd loves him for it.

He had already thanked Dave once (so now we had Dave watching Boris praising Dave) when suddenly he pounced. “I notice from reading the papers that it's no time for triumphalism,” he noted drily, for this has been Dave's mantra. Now Boris peered into the crowd, already giggling, until he spotted his leader. “Dave!” he cried, his arm going up in mad salute. “Can I call you Dave?” he cried. “Yes I can!” Now he added: “I hope you will allow me to remind you in a strictly non-triumphalist way of some of the things we have done in City Hall.” Let the triumphalism begin! And so it did. Boris trotted out his achievements to date, flagged up more to come, attacked Labour, defended City bankers.

At the end there was an instant standing ovation, but even as the wolves whistled Boris slipped out and Dave, watching Boris but Boris no longer watching Dave, slipped out, too. The Dave and Boris show was over, for now.

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