Veronica Lee: Have you something to tell us, lads?

Film portrayals of lesbians suggest they are simply to be ogled or laughed at

You would think in this age of civil partnerships that heterosexual men might have got over themselves about lesbians. After all, no television soap or drama is complete without one, they read the news and present prime-time TV, and even Lindsay Lohan's amour with Sam Ronson doesn't raise an eyebrow any more. Lesbians are just so boringly normal.

But no, sadly there are straight men out there who still seek to portray lesbians as weird, dangerous and predatory – and let's not forget salacious, of course – as demonstrated in Mathew Horne and James Corden's new film Lesbian Vampire Killers.

I won't detain you too long in describing the plot, such as it is, but Horne and Corden's characters find themselves in a weird village where its young women are in thrall to a bunch of lesbian vampires and they have to rescue the ladies from a life on the dark side. Leaving aside its dubious artistic merit (it has received a critical mauling) what the film says about how these young men regard gay women is rather depressing.

It's as if the film's stars sat down with writers Stewart Williams and Paul Hupfield and rather cynically worked out which words in the title sell a film to overheated and undersexed heterosexual men. Killers? Tick. Vampires? Tick. Lesbians – but only fit ones who get their kit off, mind – double tick with a cherry on top! It's a neat trick so often trotted out in media portrayals of lesbians – they're scary (bad) but sexy (good) at the same time – the perfect one-hand viewing material.

The film's creators may have thought they were producing a wacky high-concept comedy dripping with irony, but sadly all they have managed is an exploitative, mean-spirited movie whose take on lesbians is as bizarre as it is unfunny. They are there simply to be ogled or laughed at – it's Benny Hill with a coating of sapphism.

It's not quite vagina dentata territory, but Lesbian Vampire Killers perpetuates another myth – that those nasty lesbians are always trying to lure straight women into a life of cunnilingus and comfortable shoes – and the film's low point comes when Horne's girlfriend has to resist being "turned" by the vampire in chief. And I'm always suspicious of heterosexuals who are clearly titillated by what lesbians may or may not do in bed – it doesn't take Dr Freud to deduce that there are probably all sorts of homoerotic transference issues being worked out here. Is there something you're trying to to tell us, lads?

But all is not lost for those of a more refined palate who want to see lesbian lives as they really are portrayed on screen, as the London Lesbian and Gay Film Festival opens on Wednesday. One that may appeal is I Can't Think Straight, an autobiographical tale by writer and director Shamim Sarif.

It's a touching and often amusing story about two young straight woman who have to overcome all manner of religious and cultural differences before they find true love with each other. It's intelligent, feisty, witty and elegant – everything that Lesbian Vampire Killers isn't – and it's a film that Messrs Horne and Corden may like to see. But maybe not; I suspect its nipple count may be too low.

Veronica Lee is a writer and critic. London Lesbian & Gay Film Festival: www.bfi.org.uk/llgff