SEX is JUST SEX, regardless of the portrayal in movies that the act of sex we should all aspire to partake in is profoundly loving, a spiritual meeting of mind, body and soul.
SEX IS NOT LOVE. Having sex together can be [but is not limited to] an action of love, by investing the time and effort to stimulate your partner to maximum pleasure/orgasm.
AN ORGASM IS NOT LOVE. It is a biological drive, a primal/base urge both sexes possess (to varying degree between individuals, and generally heightened between the teens through early 40s, then tapering with age). The Pleasure/Reward circuit that lights up our brains with every orgasm is likely encoded in our DNA— part of our evolutionary process— incentive programming to reproduce.
Consenting partners engaged in the act of sex, often equate the pleasure of physicality with feelings of love. This is especially true for first crushes, but the notion that sex and love are synonymous is the gold standard in mainstream morality. It's proselytized by religion, parents, and the media— 'making love' the climax (excuse the pun), consummating the canonical 'happy ending.'
It is NOT an action of LOVE, in the throes of passion, to break marriage contracts of fidelity. It is, perhaps, more egregious to nix the condom to heighten erotic stimulation without knowing the sexual health and history of your partner. These are displays of their lateral orbitofrontal cortex shutting down, blocking out all reason, abandoning all behavioral control to the Pleasure/Reward circuitry in the brain.
Kind of like a gorilla. (They have a hard time with complex reasoning, and predictive modeling— examining the possible consequences of their actions.)
Historically, men are more driven by their biology, claiming to require or desire sex 5 times more than women. However, when either gender is touched appropriately, we are equally hard-wired for stimulated free nerve ending nociceptors to trigger pleasure in our brains.
SEX is NOT LOVE, no matter what your pastor, or TV, or your mother tells you. SEX is JUST SEX.
LOVE is much harder to attain than an orgasm.
In fact, I can take care of my biological need all by myself. Loving myself alone, however, leaves me so very lonely.
From biblical times, humanity has made SEX into so much more than it is because the consequences of intercourse can begin, or end life, as with STDs. Even with the advent of birth control, sex is still riskier for women then men. In 96% of all unwanted pregnancies, the woman still carries the burden of raising the child. (Choosing adoption, or to terminate— each carries their own weight, for life.) We all expect the primary parent defaults to the mother, even today. Steve Jobs is beloved, regardless that for 9 years he denied parentage to his daughter, Lisa, even after DNA testing proved he was her father. Common wisdom professes women are programmed to care for our children. We must not walk away, which is why women and men generally have sex for different reasons.
Women are usually looking to establish a deep[er] connection when we initiate or consent to intercourse. Even with hookups, most women are looking for an intimate bond, a shared emotional space, at least in the afterglow of orgasm. For women, languishing with their lover in this space is equally, if not more satisfying than the orgasm itself. (Women often use sex to draw men out of their own heads. We have for millennium, consciously, and not. You can pretend it's not true, but you'd be lying to you.)
SEX is just SEX, but if Desire— the expectation of the activation of our Pleasure/Reward circuitry— is not satisfied, a predictable pattern of behavior generally emerges.
Women who are unsatisfied sexually with their partner, are usually more unhappy with their partner's behavior in other areas of the relationship. Trying to ignore Desire, simply to stay together often leads to a life of internalized bitterness. And for 19% of married women in the U.S., their fidelity typically falls to a married man who lavishes them with attention, praise, sometimes gifts— actions their partner is not taking, and commonly mistaken as romance, when really, he's just trying to get in their pants. (Heads up, Ladies... Any guy who'll cheat on his partner with you, will [eventually] cheat on you.)
Sexually frustrated men typically withdraw, become more distant. They're less malleable. Less likely to pay attention, be supportive— from offering help with a task, to responding, without passive/aggression, to concerns and issues. This behavior leads to further discord, and less sex, perpetuating the implosion of the relationship.
SEX may be just SEX— our biological drive to reproduce— but with all the mitigating factors that come along with intercourse, the reality is SEX is 5% of the relationship when it's good. And 95% of the relationship when it is not.