What has become of me? I felt middle-aged enough, opting to watch a difficult Symbolist opera instead of attending a gig at the Barfly on Friday night. Then, for the first time in my theatre-going life, I experienced the urge to boo at a curtain call. Pelléas et Mélisande at Covent Garden was the object of my scorn - and my scorn, I don't mind admitting, was multiplied by my own horror at becoming one of those pompous oafs who boo at opera. Even bravo-ing at opera is a little unforgiveable in my opinion. "Look at me!" it blusters, "I know about opera and I'm not afraid to show it in a non-English way! Brava! Brava! I'm practically Italian!" Tossers.

Now, musically, the production was wonderful. Debussy's lovely score, which Sir Simon Rattle stirred like smelted gold, shimmered from the first four chords. The story, based on Maurice Maeterlinck's enigmatic play, is beguiling: austere, mystical, forever on the brink of revelation. Gerald Finley (below) as the villain Golaud was commanding and clear, as the lovers Angelika Kirchschlager and Simon Keenlyside (above) were haunting, and the child singer George Longwirth was a minor sensation as Yniold. The blind would have loved it.

The sighted had to contend with the silliest design seen on the London stage since... well, since the last pretentious, over-funded opera made it to these shores. Massive, expensive boxes were wheeled around and opened up to reveal nothing but the colossal arrogance of the designers, who seemed to have read the libretto and opted to ignore it entirely.

Worse were the costumes . They were supposed to be "heightened Elizabethan", but, with their fat foam haunches, looked more like the ugly love children of Elvis and Tinky Winky. Everyone I spoke to railed against their ridiculousness: my girlfriend, our director friend Prasanna, the ROH staff member we spoke to, our critic Fiona Maddocks, who has subsequently described the offending garments in her review as "bejewelled white boiler suits like roly-poly Rococo plumbers".

So when it came to the curtain call it seemed only natural: big cheer for the singers; big cheer for Simon Rattle; and then, when four trendily dressed civilians wondered on as if by accident - evidently the design team and director - I felt sufficiently emboldened to emit a big boo... but NO! Just as I was preparing to let rip, the gent on my left begin to whoop and cheer and applaud maniacally. "BRAVO!" he thundered. "BRAVO!" He clearly loved the costumes. Perhaps he had some sort of foam fetish.

Now, I recognised this chap. Where from? He may have been an important critic - though I couldn't work out who. Was it the chief exec of the Royal Opera House? Was he in charge of the Barbican? I couldn't work it out - I have a shamefully bad head for the names and faces of arts world bigwigs - but all the same felt suitably intimidated to keep schtum. I regret it now. Should have challenged him to a booing/cheering match, and settled the ensuing barney with a bout of fisticuffs. But then again what is a blog for if not the written equivalent of a boo? So: Boooooooooooooooooo!!!! Hissssssssssssssssssss!!!! As for Mr Arts Bigwig, I'm still not sure where I know him from. Just don't be surprised to see Tellytubbies: The Opera on the London stage any time soon, as he gives full vent to his passion.