Women are offended by men who whistle at them on the street because instead of the romantic admiration women enjoy, men refer to crude and impersonal sexual urges. Unlike women, men do not need an emotional context to enjoy sexual activity. If women were aroused in a similar way, they would understand the male response. Women cannot understand how men can want sex with a random unknown woman they pass in the street.

For men, even the smallest hint of a sexual attribute, such as cleavage and camel toe, is cause for speculation. Women do not have the same fascination for men's bodies. If women were aroused by a lover's genitals, more men would display their bodies provocatively as a female turn-on. Equally, women would pay for lap-dancing and pole-dancing bars as men do. Women go to see male strippers for a laugh not for erotic arousal.

Leading up to intercourse, a man becomes increasingly aroused:

• He has regular erections and masturbates;

• He is aroused by seeing a lover and thinking about sex;

• He is aroused by close body contact and kissing;

• He is aroused by touching and watching a lover undress;

• He is aroused by stimulating a lover and by being stimulated.

A man responds sexually to people in the real world. But masturbation alone depends on using memory alone to conjure up fantasies, which puts a man in a similar position to a woman. A woman does not respond to real-world stimuli but she can use surreal fantasies to achieve orgasm alone.

For most people, sexual activity either alone or with a lover is a private affair. So we rarely never see other people engaging in sexual activity. Most of us rely on fictional accounts that we see acted out or we read about. Most of this activity relates to sociable situations. Masturbatory activities are much less commonly portrayed. Men's prime focus is penetrative sex and male arousal depends erotic turn-ons such as a lover's sexual anatomy and observing how they respond to stimulation especially penetration.

Women have little interest in visual portrayals of any kind of sexual activity. Not only are women not aroused by the idea of male masturbation, they are typically disgusted by it. So men tend to keep their masturbatory activities private. Some men are more motivated to masturbate than others. Masturbation depends on a person having a creative imagination. Educated men are more inclined to masturbate as a source of release and pleasure.

Men's sexual fulfilment ultimately comes from their sex life, not from fantasies. But their fantasies lead them to believe that a woman should be aroused by what they do to her sexually. Some men need the emotional reassurance of an apparently engaged partner. This is difficult for women to understand. From a woman's perspective if a man is hassling for sex, she assumes he should be able to satisfy his needs without her engagement. She assumes that a man only needs physical stimulation to enjoy sex.

A woman reacts very little when her lover reveals his erect penis. She doesn't scream but neither does she vocalise her pleasure. A woman screams when she is unwilling. The flasher situation is clearer when we remember that the mating act is imposed on the female by the male. A man likes to think that what he is doing to woman is producing some kind of response. He's not necessarily looking for her to enjoy what he is doing.

Male expectations for a proactive lover come from porn. But few women watch porn so they never realise they could offer more than intercourse. No one explains this explicitly because it would involve admitting that women are not naturally motivated to offer sex play. A woman may feel guilty because she assumes that she is supposed to enjoy sex. A woman thinks she is supposed to make effort but she doesn't see why she should.

Women often don't appreciate that men need assistance with their arousal. Men are often too embarrassed to ask. Men assume that all women have the skills of a porn star. Many women never watch pornography. Most women do not appreciate the need for turn-ons. They are offended by men's crude sexual urges. Even women who do understand turn-ons, are not necessarily comfortable with the deceit involved in such play-acting.

A man may say he wants intercourse to last for ever but a woman notices that a man loses confidence if he is taking too long. Perhaps he realises that the woman is waiting for him to finish. A woman knows that he will not be satisfied until he has ejaculated. So she helps him by moving her hips to stimulate his penis or makes encouraging noises in time with his thrusting.

It is, at once, an interesting reflection of man's absorbing interest in sex, and his astounding ignorance of it; his desire to know and his unwillingness to face the facts; his respect for an objective, scientific approach to the problems involved and his overwhelming urge to be poetic, pornographic, literary, philosophic, traditional, and moral. (Alfred Kinsey 1948)