What’s that old Bob Monkhouse gag? “They laughed when I said I was going to be a comedian. Well, they're not laughing now."

When Madonna told Jonathan Ross that she would like to have a crack at stand-up comedy last month I was one of those cynics who thought she would be rubbish. I even wrote a piece saying that. 

But part of me thought that she’s a professional performer, an experienced entertainer and a pretty good chat show host, she could probably make a decent stab at it. 

And then I watched the clip of Madonna’s five-minute set on Jimmy Fallon’s chat show. This is, I believe, what they call car crash stand-up. That thing where you want to look away but you can’t, however horrible it gets.

I’ve always been amazed when judging comedy competitions that even the rawest rookies seem able to get from the start to the finish of their set. There are moments in Madonna’s routine when there are so many ums and aahs and pauses that you really wonder if she will make it.

I’m not even going to go into the dating-young-men material or the references to the Picassos and Warhols that she owns. OK, I know you are supposed to talk about what you know, but there are limits if you want to get your audience onside.

The best thing about this clip is that you can criticise Madonna here without being nasty and ageist. It's worse than Capegate though as it's self-inflicted, not accidental. This is nothing to do with mutton dressed as lamb or a middle-aged person trying to be cool. It is just someone doing something they think they might be able to do and it turns out that they are not very good. Maybe she will say it was all a prank.

I wonder what her assistants said to her when she came offstage.

See the routine here. Warning - you may not be able to unsee it.