I confess: I went to see Twilight: New Moon on the day it came out, and I loved it. It’s one long, drawn out moment of sexual tension, helped along by plenty of rock-hard abs. (Team Jacob!) What’s not to love? But it doesn’t stop at eye candy. There’s a scene in this latest instalment of Stephanie Meyer’s sparkly vampiric restraint-epic where everything goes a bit meta. It’s about a third of the way through when lip-biting necrophiliac Bella Swan goes to see a zombie movie with her friend Jessica (who looks and acts like a refugee from High School Musical). As they leave the cinema we’re treated to Jessica’s opinions on the film, which mainly consist of her bemoaning its lack of ‘hot guys’ and showing derision for its supposed status as a metaphor for capitalism. Twilight, of course, is nothing but hot guys. Zombies… Vampires… D’you get it?

You’ll forgive me for paraphrasing; I couldn’t take detailed notes in the screening, as a Moleskine at a festival of fantasy lust is terribly gauche. Anyway, unexpected Wes Craven moment dealt with, New Moon soon gets back to the important business of finding spurious reasons for impossibly attractive men to remove their shirts, and it becomes clear where the film’s priorities lie. But is Twilight really an economic metaphor, too? Or is it just a festival of all things pop-tween, nothing more than what the Times critic Kevin Maher called “the cinematic equivalent of a Jonas Brothers concert”? With all that sexual tension flying around, it’s hard to think otherwise.

But it’s old news that Sci-Fi and Fantasy are vehicles for commentary on the real world. Everyone’s familiar with the ulterior motives of Narnia, so it’s not exactly groundbreaking to suggest that the most recent fantasy sensation has overtones beyond bloodsucking and hormonal angst. Hell, vampire stories come with their own illustrious history of allegory; since Bram Stoker’s seminal 1897 novel, the vampire has meant desire, depravity, and promiscuity. These qualities are knowingly subverted in Twilight, with the vampire heroes instead opting for monogamy and chastity. Twilight reclaims a well-worn tale of sexual desire and makes it palatable to the Bible Belt. The message is clear: abstinence is sexy.

You know all this. And yet the theme doesn’t quite work, not least because telling the tween (for the tween is absolutely the target for these films and books) not to have sex will only make them think about it more. South Park’s Jonas Brothers episode is a much more adept critique of the JoBro/abstinence phenomenon than I could manage, and I recommend you check it out. But there’s more to be said; there’s something darker afoot in Twilight.

For an economy dependent on using sex to sell products, the virgin tween market has always been a challenge. But now Disney seems to have cracked it; to appeal to a demographic poised on the brink of sexual oblivion, all you have to do is push them over the edge. Forget about ponies and sleepovers; the innocent tween must die. Surround them with sex, tell them not to do it, and make everything glittery to ease the transition.

Evidence that this strategy is working, and that the process of growing up is becoming an overnight switchover from childhood to libidinous adolescence, can be found in the diminishing market for anything squeaky clean. Disney tween queen Miley Cyrus was photographed in a provocative pose for Vanity Fair at age 15 and, still underage in America, she pole-danced at the 2009 Teen Choice Awards. Her estimated worth is around $1 billion, making her the world’s richest teen. And it’s difficult to defend her as child-friendly.

It’s happened in the US, and it’s happening here. Take Jedward: people were surprised by the length of time that they managed to cling on in X Factor, but not Louis Walsh. He assumed that the twins’ market was tweens, and that kids would vote for someone fun, someone like them. He was wrong; the tweens vote for Lloyd, a similar age to Jedward but more of the boyfriend type than the mischievous classmate. The people keeping Jedward in were twentysomethings with a sense of irony and anyone wanting to annoy Simon Cowell, and both of these camps have far less tenacity than the tween stuck at home with their parents every Saturday night.

Jedward’s departure proved that the tween is dead. Non-threatening is over; 11-13 year olds are demanding something darker, and the promise of more to come with every hint of burgeoning sexuality. The relentless drive of capitalism has led us further towards the sexualisation of children, and big corporations like Disney are happy to keep it that way. Maybe Twilight isn’t a metaphor for capitalism, but it certainly embodies its darker side.

Charlotte is the Guardian Student Columnist of the Year