Sex in your 20s

"Is about living out your fantasies"

Catherine Townsend, 29, is the author of Breaking the Rules ($24.99; Jon Murray)

"I was a pretty wild teenager. I lost my virginity at 16, in my boyfriend's bedroom, played out to the soundtrack of Led Zepplin's "Stairway to Heaven". But although it was a disappointment (the whole act was over before the guitar solo finished), from that moment I craved contact with the opposite sex.

By the time I'd reached my third decade, I thought I knew a lot about sex, but now, as I climb into my fourth, I realize I didn't really know much at all.

My 20s were a time to experiment. There were the one, two, and three-night stands; the lesbian fling with my classmate who had a supermodel body that I used to eat chocolate cake off; the scuba diving instructor who gave me my first orgasm through oral sex; and the man who taught me that men could have multiple orgasms, as well.

There was my first threesome, too, which happened, at least in part, because there was nothing good on television. I had been out dancing with a female friend from university and a mutual male friend when we stumbled back into my flat at 4am for a nightcap. I was channel surfing while drinking vodka when I heard amorous noises coming from the bedroom. I was single and, at the time, the choice between sexual ecstasy and infomercials seemed an easy one. The experience was fun and unforgettable; I relished the sensation of being pleasured by more than one person, and because there was no unrequited love on anyone's part, we all remained friends...

Sex in your 30s

"Is about keeping the passion alive"

Tilly Bagshaw, 34, says thirty-something sex is seriously under-rated. She is the author of Do Not Disturb ($32.99, Orion)

Writing an article about sex in your 30s is the journalistic equivalent of a suicide mission: a long, painful crawl across a cliché minefield. As far as I can gather, you're either supposed to say: "Sex? What sex?" or "Oh my God, it's incredible! I have so much more confidence in my body now than I did in my 20s and my husband is a Sting-like tantric love god." There is no in between.

For many of us 30-something sex means married sex. But even as I write that sentence I can hear the clichés flying at me like shrapnel. Marriage is the end of your sex life! Men are always gagging for sex, it's the wives who are too tired. Nothing kills passion like a baby.

Like most clichés, there is a grain of truth in all of the above, but only a grain. Sadly, one of the few similarities between sex in your 20s and sex in your 30s is that women still lie about it; to men, to each other and sometimes even to themselves.

Strangely, in our modern, post-feminist era, one of the biggest taboos is the subject of waning male libido. At least half of my married, thirty-something girlfriends complain about their husbands' lack of interest in sex, but you will rarely see this written about in the press. As one friend put it, "I'm telling you Tills, Claudia Schiffer could be pole dancing naked right under his nose and if the football's on, he'd tell her to bugger off."

Sex in your 40s

"Is hard work, but plenty of fun..."

By Wendy Merrill, 43, is the author of Falling Into Manholes ($32.99; Pan Macmillan)

As a somewhat precocious child, I remember having two ambitions. 1) To be comfortable on any barstool in the world 2) To be a world-class lover. Achieving aspiration number one was easy and as a result, so was I! Turns out, I was quite the lush and consequently my memory of sex in my 20s is a bit hazy. What I do remember, however, is that I often mistook sexual chemistry for commitment. I was a serial mater, always jumping into bed with the wrong guy and then spending years trying to make it work.

In my 30s, I did the exact opposite and confused commitment with lack of chemistry. I married a "nice guy" who I loved but wasn't insanely attracted to and as a result (unlike my earlier chemistry experiments) married sex was safe, predictable, and boring. I ended up faking both my orgasms and my relationship, and after what seemed like five very long years, I celebrated my 40th birthday by leaving my marriage.

And then suddenly there I was, single and having sex with new people all over again in my fifth decade.

Older but apparently none the wiser, dating in my early 40s was described by my married-with-children mental health professional sister Robin as "Wendy's catch-and-release program."

First there was Timmy, a long-distance relationship with a man whom I had never actually met, characterized by phone and cyber sex. Never one for talking dirty, I suddenly became phone sex girl, and briefly considered starting my own "Hot line" business, perhaps calling it "No Hang Ups," or "Bitches without Borders." In some ways Timmy was the ideal man because he was more or less a figment of my imagination. When we finally met, he turned out to be a bit of a drunk with massive mother issues, and the reality of our interactions put an end to the fantasy...

Read more about these three writers' experiences in the October issue of marie claire.