The question of male female attraction and sexuality has remained shrouded in mystery. For a proper answer to this question, we must go to the roots of creation, life, nature of emotions and the cause of sexual attraction. These are vast chapters and there are plenty of literature on it (without explaining it properly). However, we will restrict our reply to few salient features.
Mobility of sense organs, which are nothing but the different quantum level interactions, is the sign of life. The mobility varies from local mobility of various parts without displacement of the base (like in plants) to interaction with distant objects like intercepting light from far off galaxies by our eye. The development of sense organs are related to the agencies of mobility (feet) in an inverse relation - the number of feet determines the number of sense organs. For plants with their numerous roots and bacteria with their numerous tentacles, there is only only one sense organ - that of touch. For higher life forms (less number of feet), the number of sense organs increase from one to two, three, and four for animals (fully developped ones - they have deficiency in at least one sense organ) and finally five only for human beings. Hence only human beings can copulate facing each other in their natural posture. All other animals have to bend. The monkies in spite of four legs come close to human beings. Hence they were predecessors of human beings in the evolutionary sequence in that sense and not in the sense espouched by Darwin - they are nou our fore-fathers.
Sex along with hunger, fear and sleep (rest) are the four common features of all living beings including plants. The only differentiating character between them and human beings is the ability to plan an action - intellect. Animals can only respond to these four natural sensory behaviour instantaneously, but they cannot plan long term like human beings. Thus sex, which is basically related to the sense of touch, is a natural instinct of all. But in case of humans, the response to it is conditioned by two factors - one natural and the other cultural (related to use of memory in specific ways to plan future action).
Attraction comes due to four reasons. The first is habit. We like something when we are habituated with - mothers food tastes best. The second is super-imposition. We assume something as something else without a proper basis (the face of my beloved is like moon and her lips are like cherry fruit, my lover is mine only, I can give up everything for my love, etc) and then like it like a stupid. (There is reason for such behavior, but we are leaving it out.) The third is recollection - we knew something in the past, but sepated for a long time and suddenly come across it. Such encounter brings in sweet memories and we like it. The last one is common to all - the harmonious interaction of sense organs with their objects of perception. This harmoniousness is conditioned by biological evolution also.
In case of human beings, the consciousness, intellect, mind and body are four common factors. Their degree of evolution only varies to provide variety. Of these, the first two are internal to the body and the last two interact with external bodies. The nature of feminity is to confine (negative charge of an electron confines positive charge of proton in an atom, the females confine the foetus, etc). The nature of masculinity is procreation (the number of protons determines the number of electrons - hence the nature of chemical reaction, the sperm of males grows in the female womb to become the child). Where the consciousness and intellect are confined within the dominant mind and body, it gives rise to feminity and vice versa. Hence females tend to be satisfied by more intellectual involvement with less males and males like to have more external female bodies than soul mates.
The growth of female body is different from the growth of male bodies. With the onset of pubic hair, the females show the nature of the gross variety of negative charge (soma), whose nature is contraction. Hence at this age girls feel shy. With the onset of menstruation, girls show the medium nature of negative charge (gandharva), whose nature is sensessional. Hence their sensetivity grows immensely. Simultaneously, they gloss over many things. Thus, they often giggle for no obvious reason. With the complete formation of the breast the opposite sensitivity takes over (paavaka). It creates the excessive internal heat that can be seen in the most fertile period and can be sensed simply by putting the back of the hand behind their anus. However, the overall effect makes them shy also. This shyness prevents them from indulging from sex, but is gradually overcome with age. During the adolescent period, if the girls are not educated about the effects of sex, they tend to go for it increasingly. Thus, nature has given them a protective ring by making then open up from within in a very slow process unlike men, who are aroused instantaneously. This shows the effect of not only biology, but also culture. Biologically, since the nature of feminity is confinement, they would prefer to confine as many male organs as they can have. Sex education and culture only restraints them.
In the case of men, it is different. When they desire, they arouse instantly. This requires the prostrate gland to tighten the base of the penis to keep it erect. The strength of this wears down with age, Thus, above 45, most men have prostrate gland problem. With the increase of permissivity, men get excited quickly, but fail to sustain it for long enough. Usually they take recourse to masturbation, which takes a toll on the prostrate gland and tends to appear as back ache. Thus, with age, they become less and less "fit" for sex, whereas women remain fit or may be increase their fitness by reducing shyness. This is reflected in the large number of middle aged ladies having a not so fulfilling sex life. But here also nature has provided a safety ring. The secretions of post-menopausal women are harmful to the men. Hence sex with post-menopausal women has been prohibited by the medicinemen.
This does not mean any aspersion on females. We must accept our bodies as it is and try to enjoy what we have got. The feminist movement only shows the refusal of some to respect the laws of Nature and protray them as something they are not.
Finally, BE WHAT YOU ARE AND ENJOY WHAT YOU HAVE GOT. But remember - everything has a price (not monitary). You are full. So you can get something only when you lose something like a full cup can get some more only after it gives out some of its contents. You can try to bring in something, but you cannot determine what you have to give up in return.