Its how they get what they want from men, and men who haven't managed to stop being controlled by their sexual desire are very easy to manipulate from the perspective of women. And the sad thing is most men are so hooked on sex and controlled by their biological urges that they don't really mind.

"The basic principle of 'sex as a reward' does not vary from woman to woman. They all offer themselves to a man, stress their charms and then, providing he has performed his 'tricks' satisfactorily, reward him...one of the results of this female system of sex as a reward is that a man with strong sexual needs must be more obedient to women than others..." - Esther Vilar