Us ladies tend to get our panties in a twist when we feel used for sex.

Nothing has the ability to boil our blood quicker than a roll in the hay where the only result is a notch on his belt. Yet all that energy spent hating manwhores may seem a bit hypocritical if we were to sit down and examine why we slept with him. A need to get off? One too many glasses of Pinot Grigio? A slight sense of IOU after a pricey meal? To get over somebody else? To feel preeeety? All Women Are Prostitutes. Seriously?

University of Texas at Austin clinical psychologist Cindy M. Meston and evolutionary psychologist David M. Buss set out to find the blunt answers in their new book, Why Women Have Sex: Understanding Sexual Motivation—From Adventure to Revenge (And Everything in Between).

As The Daily Mail reports:

For most women, passionate desire languishes in the lower reaches of the list, somewhere below 'to get presents from him,' 'to shut him up' and even 'for fun'... the reasons to have sex become far more mundane, or even acquisitive, such as 'So he'll take the rubbish out' or 'Because he took me for a meal'. The key finding of the book is that men are, on some level, physically attracted to most women, yet women are left sexually cold by most men.

The Daily Mail writer explains away these, er, creative reasons for sex by placing men square in SIMPLE and woman's own a libido that's "intricate as a weaver bird's nest—a complex interlacing of disparate feelings, needs and promises."

According the book, 84 percent of those surveyed have sex plainly to "keep their partners quiet or to get help with the chores." And one in ten admit to having sex for presents.

How's that for romance?

Sex, like anything else, can become a chore, we realize. But, as the book goes on to explain, early relationship sex for women is about physical attraction (check) and, after the magnetism has waned in a longer-term relationship, is often motivated as a means of emotionally connecting with a partner (check again). While we hope that most American women don't get to the point of using it as a pacifier, we understand that the bodice-ripping, madly-in-love sex experienced early in a relationship inevitably morphs into a more comforting, comfortable routine.

Readers: what are your reasons for having sex?