So what's your number? Is it 1, 10, or 20? Is it 437? Or is it nobody's business but your own? The last point may be true, and there's every chance that like many women you feel a bit uncomfortable talking about the number of men you've slept with.
Which is tricky, because the subject does have a habit of cropping up. And even in these supposedly enlightened times, women still worry about what both friends and potential boyfriends think of their number.
"Even in today's so-called sexually equal and liberated days, many women still worry about what the number of sexual partners they've had says about their character," says Paula Hall, relationship psychotherapist for www.TheRelationshipSpecialists.com.
"Too few (partners) may leave people thinking they're a prude, whereas too many might indicate they're a slut. Women are more likely to understate the number of men they've slept with to both friends and potential boyfriends."
Women lie about their number
Research shows that, on average, women have around seven sexual partners in their lifetimes, and also that many women lie about their true number, especially if they consider it a little on the high side.
In fact, a study released last year found that a third of women lied to new partners about past sexual encounters, and that two-thirds of those who did knocked a few off the list rather than adding a few on.
An interesting study from Ohio University in the US confirmed the results. Women were asked about their magic number, but while some were told that researchers would read the results, others were told they'd be anonymous. The average figure for those who thought they'd be read was 2.6, and for those who didn't 3.4.
There was another twist to this research. A third group were told they were being monitored by a lie detector, and among these women the figure leapt to 4.6.
Men and children
Which all begs an obvious question. Why do women still lie about their sexual encounters? After all, men are happy to boast about past sexual conquests, so why do women still feel the need to act the innocent?
Connected to that is the question, do men actually care? According to Paula Hall, the answer is that, unfortunately, some of them might.
"A lot of men still see getting a women into bed as a sign of their sexual prowess and of their desirability," she says. "When a woman says she has slept with many previous partner then their sense of achievement will be less."
It could be that pesky old evolution plays a part in all this. Parental investment theory is a part of evolutionary biology that says men want to invest their time and resources in their own offspring, not in the offspring of other men.
We're not casting aspersions here, but if you think about it, barring a blood test a man can never be 100 percent sure that a child is his.
"This means that men may be biologically programmed to prefer a woman who has had less partners, because therefore there will be a greater chance that any resulting conception will be their offspring," says Hall.
Is there a 'wrong' number?
Hall also points out that we've come a long way since we were running around chasing woolly mammoths with clubs, so we shouldn't be slaves to our primitive genes. But a study conducted jointly by a men's website and a women's magazine suggested that even most women still think women can have a 'wrong' number, which the study rather unfortunately dubbed the 'slut number'.
According to the poll of thousands of women, 37 percent believe a woman's slut number is 20 sexual partners or more, while a 'more conservative' 35 percent put the figure at just 10. Only 9 percent of respondents said that women can never be sluts, which perhaps shows just how far feminism has to go.
There is a feeling that women can't be right, whatever figure they choose to own up to. Sex and relationship therapists are reporting increased numbers of women worrying about having too few partners in their pasts. Perhaps in the fast-moving world of modern dating, experience is starting to trump innocence as an attractive female trait.
Keep quiet, then be honest
One obvious answer to all this is to keep your number to yourself, at least for as long as you can.
"What does a person, especially a woman, have to gain by reporting her number?" asks dating expert Paula Rosdol. "From a woman's viewpoint, if she does she's in a no-win situation. Too few partners and one may appear naïve or inexperienced. Too many partners and one may appear 'used goods'."
"My advice to dating women is to keep your number to yourself. It's nobody's business but your own. There's nothing wrong with not revealing all and entertaining a bit of mystery."
Which is fine in the very early stages of a relationship, but if a fling turns into something more substantial the question is bound to come up sooner or later. One strategy might be to use it as a kind of test. If a man you think you've made a real connection with asks about your magic number, be entirely honest about it and demand the same honesty from him. Then judge his instant reaction. If your answer makes him unhappy, proceed only with the utmost caution.
Oh, unless the number really is 437 of course. In that case, at least forgive him the nervous giggle.