News Flash!  Men are more satisfied with one night stands than women!

According to an unscientific Internet poll published in the journal "Human Nature," half the women who responded are unhappy after casual sex, whereas four out of five men are happy.  While men felt more content, confident and sexually satisfied after meaningless sex, women were more likely to feel used and let down.

Durham University professor Anne Campbell, who led the research, said the results demonstrate how there is no evolutionary advantage for women in one night stands.  "In evolutionary terms women bear the brunt of parental care and it has been generally thought that it was to their advantage to choose their mate carefully and remain faithful to make sure that their mate had no reason to believe he was raising another man’s child.  Recently, biologists have suggested that females could benefit from mating with many men - it would increase the genetic diversity of their children, and, if a high quality man would not stay with them forever, they might at least get his excellent genes for their child."

I believe the equation is more simple.  You know the old saying:  "Men use love to get sex.  Women use sex to get love."  Hence, men are getting "what they want" with one night stands, whereas women are not.

More at BBC