She even flirts with a guy I used to fancy, coyly placing ants in his mouth

Saturday night Sunday morning

This is too mad. How does Erin, a four-year-old child, come to know all the words to the Sex Pistols' "Anarchy in the UK?" Of course, Finsbury Park is full to bursting with ageing punks, their thinning hair scraped into wobbly mohicans, punching each other with glee at the return of their idols. But Erin's hero is "Butterfly Magic" Barbie. Or so we thought. I don't know why we're so surprised. An hour earlier, she was sitting on her mother's shoulders copying Iggy Pop's every gyration. "Oh, my God," sighs Barbara. "I've created a monster. I've raised a Damon Albarn stage-school kid nightmare."

They take it in turn to be bonkers. The year I met Barbara, we bonded so quickly that she and Erin spent New Year's Eve with my family. Barbara is not remotely alcoholic, but she has, we've decided, a chemical imbalance to alcohol. One sip and she's imbalanced. Within minutes of arriving, she had placed Erin's frilly pink hairband on my father's head. She obsessively played "Your Song" by Elton John until we thought we'd break down and then clung to my mother's arm when she tried to go to bed. "But you can't go to bed. You've got curly hair." Babs, Lisa and I all crashed in one bed. When we woke up, one of the rubber duckies in the bath was marked "BARBARA" in thick blue letters, and Lisa had two cigarettes in her pyjama pocket. A Polaroid from the start of the evening shows Barbara holding Erin on her hip. "Morticia and Courtney" it says, in drunken felt tip.

Barbara is as pale, raven haired and sombre (sober) as Erin is blonde, attention seeking and frenzied. If Erin is throwing a tantrum, the only way to calm her down is to hold her in front of a mirror. She is hypnotised by her own beauty. Her mother, like all mothers, encourages it. "I don't know what I would have done if I'd had an ugly kid." A mutual friend once proudly showed us his baby photos. He was a fat-faced goofy little runt but sweet with it. Barbara, however, was horrified: "If you were my child, I would have swapped you for a tub of margarine."

Resplendent in her Barbie rucksack and pink bows, Erin is the life and soul of Finsbury Park. As the adults mutter about "ver Pistols" selling out, she moves from table to table, jumping, skipping, doing ballet. When another kid falls over and starts crying, Erin cries harder. "I like your hair," she whispers to a hardcore green-haired punk. She even flirts with a guy I used to fancy, coyly placing ants in his mouth.

She is only overshadowed by the arrival of more seasoned attention-seekers. Dressed in Gucci to check out the anti-fashion legends, Liam'n'Patsy and Johnny Depp and Kate Moss pull up in tinted limos. A number of photographers try to take their picture. Patsy neither smiles nor grabs the camera, but quietly moans "no, please, not now", as if it were her grandmother's funeral, not the daft punk cabaret it is.

Everyone is talking about the "Patsy" tattoo that Liam has had done on his upper arm. "How did she do it? How did she get him? Why are they together?" pout indignant younger girls with ambition and chic, short haircuts. "Maybe," I venture, "they are in love with each other." Everyone looks at me funny. A girl I know takes a photo of Kate and Johnny and then promptly loses the camera. After scouring Finsbury Park, drunk and desperate, she checks the men's toilet. Johnny Depp walks in. He stares at her and drawls "Alright, man? Watcha up to?" Stuttering, she explains that she has lost her camera. He bends down and begins to check behind the drains with her.

I don't care what anyone says - the Pistols are great. This is largely because they play the songs as they sound on record. None of Lou Reed's: "All right. I'll do 'Walk On The Wild Side', but without the bassline and to the tune of a gibbon screaming." They romp through a note perfect "Anarchy in the UK" and Erin goes pogo mad. As she twirls, a kindly man tries to make kiddy small talk with her. "Erin, Erin - are you a punk? Are you punky?" She eyes him coolly, straightens a bunch of her crimped blonde hair, and then spits a mouthful of orange juice in his face. Johnny Rotten couldn't have said it better himself.