Strong sex drive
Multifarious of sex that is nature has not only given women a two prong and exponentially stronger sex drive than men, it has also given women the ability to experience a far greater quantity, intensity, and variety of sexual pleasure and orgasm than men. This is nature's way of motivating a woman to seek out sexual activity considering the risk she bears in doing so. (Even though today's contraceptives greatly reduce these risks, they do nothing to diminish the internal triggers that drive a woman's need for a variety of sex and sex partners. If anything, this reduction of risk intensifies her drive to seek pleasure.
We the big male also has a much simpler sex drive than a woman. We simply wants to mate with any female he finds desirable. The longer we is denie sex, the stronger our desire grows and the criterion by which we finds a woman desirable lowers. Since it is the woman who decides if he will be allowed to have sex with her or not, our desire for woman sexually is also linked to the desire for her approval. As man becomes more interested in her the desire to please her as a way to get sex can become overwhelming for man.