David Buss is an evolutionary psychologist. Recently, the work of evolutionary theorists in explaining sexual behavior has attracted the most attention. Buss and others in his field have studied the trends of sexual attraction and determined that both men and women are interested in sexual behaviors that will increase their chances of reproducing.
Males tend to desire multiple secual partners because the more partners they have, the better their chances of producing offspring. Females, on the other hand, generally are content with only a few partners throughout their lives. They value stability and ability of their partner to support any offspring resulting from a sexual union.