Ever had sex when you didn't really want to? Shhh, me too! Once upon a time, anyway. But you're not alone: nearly half of women under 30 have had the same experience, according to a new survey by Company magazine. Tell me something I didn't know. The majority of the respondents felt pressured into doing it; the rest were either drunk or scared of angering their partner.

To get real for a moment: women have been known to dispense a sexual favour or two simply to shut their man up when he's getting a bit pesty. After all, men sometimes fake orgasms for the same reason. But when you're already naked with somebody, it's not easy to say: "Actually, I've gone off this idea. Do you mind if we watch Graham Norton instead?" And if you're drunk as well, it's simpler just to lie back and get it over with, unless you want to try putting him off with 10 minutes of heaving sobs over a long-dead kitten. Post-ladettes, there's a sense that being drunk somehow gives women power. It doesn't.

Despite the best efforts of sex educators, we are still not listening to ourselves enough. When I was growing up, "sex" seemed to mean "a period of intimate activity terminated by a male orgasm". I don't know if things have changed much, because it has never been in society's interests to teach girls how to say no.

A young woman's sexuality is often at odds with her emotions. It's definitely at odds with her self-image. I was first introduced to the concept of the "frigid whore" around the age of 14. It was a catch-all expression of disgust at female sexuality, when a boy could not get what he wanted, when he wanted it. Years later, I explored this in my first novel, Clever Girl. But I could have done without the experiences, frankly.

We live, apparently, in an age of "female empowerment". This weak, clumsy expression makes a mockery of its own concept; its feeble inclusiveness just smothers the idea in politically correct fluff. I'm pleased to read about young women running successful businesses while appearing to organise their love lives in much the same way. But even while I'm thinking "Go girl", I'm wondering if we've really got our house in order. There is enormous tension between what women strive for and what we feel inside. We play roles because we've absorbed the idea that we're imperfect and in need of constant improvement. The media tell us we must be hypersexual, "ready" at all times. If we aren't, we are dull and, worse, fraudulent.

Luckily, I'm now old enough not to feel the need to talk tough, and pretend I've been in control for every minute of my life. I haven't, and any woman who says she has is a liar, or in stupendous denial. But there's a lot of it about, which is why I'm very glad Company has finally sent this particular sacred cow to very public slaughter.

Tania Glyde is the author of 'Clever Girl' and 'Junk DNA'. She gives advice on sex in 'Time Out' magazine