I recently read an article in The Atlantic titled "Nobody Should Care About a Woman’s ‘Body Count’". The original is paywalled, but a non-paywalled version may be found here. I'm not going to excerpt it here, but I recommend reading it for yourself if the subject interests you. Basically, the author is arguing that it doesn't matter how many sexual partners a woman has had, and it shouldn't affect her as far as desirability is concerned.
I'd argue that it does, indeed, matter: and that it also matters as far as men are concerned. Admittedly, my viewpoint is conditioned by my Christian faith and having many years' experience as a pastor in dealing with relationships, good and bad. I will add that it wasn't always that way. In my younger days, I had relationships that I now regret, that were more "what can I get out of it?" rather than "what can I put into it?". I fear many of us can say the same. I wish we could have greater wisdom when we were young . . . it would avoid a lot of the damage we do to ourselves, and others, in those "salad days, when we were green in judgment". Unfortunately, life's not like that.
The huge damage inflicted on meaningful relationships by the "hookup culture" is that it's taken what is (or should be) the most important bonding experience a couple can share, and turned it into a cheap commodity, a voyeur's pornographic fulfilment, a search for new toys to give a more "profound" physical experience. For centuries - indeed, millennia - the sexual relationship was considered the physical expression of an existing spiritual and societal bond or "contract". Whether in a romantic relationship or an arranged one, the contract of marriage was supposed to precede the act of marriage (i.e. sex). Admittedly, this was often honored more in the breach than in the observance, but the theory nevertheless held sway, and governed human society for a very, very long time, no matter what culture or nationality or religion was involved. The sexual revolution stood that theory on its head. Sex was no longer a means of expressing that pre-existing bond. Instead, it became divorced from the bond, becoming no more than a casual encounter that might, or might not, lead to something more intimate in the mental and spiritual sense.
I think the general acceptance of that divorce, and the "commoditization" of sex, have caused immense damage to human relationships. It's long been said that a woman can't give herself sexually to a man without inevitably committing a part of her personality, her very being, in the exchange. I know modern psychologists and anthropologists decry this, but in my pastoral experience, I'd say there's a lot of truth in that old saw. I think women do, inevitably, commit a lot more of themselves when things get physical than men do. After all, the woman is letting someone else enter her. She's involved in an act that, absent external chemical or other intervention, is supposed to open the way to new life growing within her. In other words, the creative aspect of sex is something intrinsic to her reaction and response. It can't be otherwise, because only she can bear a child. Men can participate in the initial act, but they don't face the prospect of carrying another living human being inside them for nine months. Inevitably, for them, sex is more physical, less mental and spiritual, less bound-up in creation and more in recreation.
I've been struck by the number of women who've expressed regret to me about having had too many casual sexual encounters in their younger days. It's far from infrequent. They speak of having "wasted intimacy on those who didn't deserve it", or "gone along to get along", or submitted to the "if it feels good, do it" zeitgeist. Now, in later life, they wish they hadn't, and feel that the intimacy they've achieved with a long-term partner just isn't the same as if they'd been less experienced and more committed. They've seldom linked that to the creative aspect of sex from a woman's perspective, but I think that relationship can be demonstrated - at least to my satisfaction. Others may differ, of course.
Even men, if they're honest, will agree that there's a vast difference between "having sex" and "making love". The former can be impartial, almost agnostic, a mere exchange of bodily fluids, sometimes a commercial transaction rather than a human interaction. The latter is a giving of self combined with a receiving of the gift of self from another, an exchange, a sharing, a duality. I had a conversation once with a woman who was far more sexually "liberated" than I was. She challenged me to describe how making love to my wife was any different from making love to any woman. I thought for a moment, then answered that I wouldn't be "making love" with someone I didn't actually love. The physical act of sex, under those conditions, would not be "love-making" at all. On the other hand, making love with the woman I love was like coming home. I belonged there. When she welcomed me into her body, she welcomed me into her soul as well, and renewed her presence in mine at the same time. The other woman thought for a long, long moment in silence, and then said, with tears in her eyes, "I've never known anything like that... but now I wish I did."
The tragedy is that the more we devalue sex, the more we make it merely another physical transaction instead of something soul-deep, the less it can be a pathway to that level of intimacy. I've worked with couples where one or both partners had previously had literally hundreds of sexual encounters with others before they married. Almost universally, I found that their own physical relationship lacked any aspect or feeling of union, of becoming one spiritually and mentally as well as physically. It was effectively no more than mutual masturbation, because they had reduced sex to that level before they met each other. They no longer were able to give themselves in the act of marriage, because it was no longer the act of marriage at all. It was just another thing, something to do to pass the time or feel good before tackling other, more important things. Other couples who'd had dozens, rather than hundreds, of prior sexual relationships experienced something of the same difficulty, although to a lesser extent than those who'd "burned out" their sexuality by going to extremes. As a rule of thumb, I found that couples who'd had few romantic and (particularly) physical relationships before marriage found their marital bond (including the physical) much more meaningful and fulfilling than others who'd been more "experienced" ("jaded" or "burned-out" might be better terms).
Notice that I haven't brought God or religion into this at all. These appear to be human actions and reactions regardless of faith. When a couple has religious beliefs as well, the latter appear to reinforce and strengthen and elevate their bond to a whole new level, and I'm profoundly grateful to have been able to help some of them achieve that. However, even in the absence of faith, the basic make-up of the human psyche appears to be consistent. Abuse intimacy, and one can no longer experience it to its fullest extent. At its worst, one may no longer be able to experience it at all. The number of sexual partners one has had - whether one is male or female - is therefore, in my experience, a significant indicator of the likelihood - or otherwise - of potential or actual problems in a subsequent permanent relationship.
I know my views will be controversial, particularly to those with a more liberated perspective. Therefore, I invite readers to contribute their thoughts in Comments. I think we might all benefit from a wider discussion of this issue.