The only reason women are assumed to orgasm without ever being mentally aroused is because most women are unaware of what is involved in sexual response. They observe men and conclude that only physical stimulation is required to achieve orgasm. Women overlook the significance of a man having an erection. They are oblivious to (or thoroughly shocked by) what goes on inside the male brain. Women define orgasm in terms of the emotional feelings they experience rather than eroticism as men do. But orgasm must arise in the same way regardless of sex or orientation.
Even without any scientific understanding, we can draw conclusions about how men achieve orgasm by observing their orgasm techniques. A man massages the shaft of his penis to get an erection only once he is ready to engage in sexual activity, which means that his brain also responds. A psychological erotic trigger causes the brain to increase the blood flow to the genitals. Young boys may have erections spontaneously in non-erotic situations. Many younger men wake every morning with an erection. But for the most part, adult men are aroused because their minds respond to erotic stimuli, such as the physical or imagined presence of an attractive partner.
Kinsey found that some men do not fantasise when masturbating. We think of fantasy as a consciously imagined scenario that overrides or embellishes a person’s current actual circumstances. But the critical issue is whether the brain is positively affected by erotic stimuli (either visual, imagined or sensory). No adult can orgasm while they are solving a problem or engaging in conversation. Adults orgasm as a result of the brain’s response to eroticism, which motivates them to stimulate their genitals instinctively.[i]
A man assumes that arousal equates to physical stimulation because he discounts any preliminary mental activity. A man can be aroused by erotic stimuli throughout the day. So by the time he gets an opportunity for sexual activity (even masturbation), a man wants to apply physical stimulation to complete his arousal cycle. But there are no real-world triggers that cause female arousal. So a woman is not constantly aroused. Personally, I knew from masturbation, that orgasm involves taking a state of mental arousal to orgasm by applying instinctive stimulation. But I did not apply this knowledge to sex. Later, I realised that I was not responding with a lover because I was not aroused. I concluded that I could not use surreal fantasy with a lover because of the level of concentration on fantasy required. My lover is not a sex object. I am not aroused by his nudity or his genitals. I am not even aroused by the idea of his erect penis penetrating my vagina.
[i] … sexual response is primarily a function of the nervous system. (Alfred Kinsey)
Excerpt from Understanding Sexual Response (ISBN 978-0956-894762)