In North America we like our sex the way we like our clothes ­ with labels. Perhaps reducing sexuality to categories makes us feel safe. Maybe we hope that by naming something we can understand it. But can we? What if the picture blurs?

    Those are the kind of questions which interest education professor Didi Khayatt. She is conducting a six-year study of how "lesbian" desire is expressed in Egypt. "In the West, we've come to believe in the existence of discrete sexual categories, and use them to describe our identities as if they were immutable, and understood and accepted by everyone," says Khayatt.

    Curiously, Arabic has no words for homosexuality or heterosexuality, although there are words in the language for acts considered to be perversions (such as sodomy or bestiality). "Arabic recognizes same-gender sex for men, but there is no equivalent recognition for women.

    "I hope to find out how Egyptian women conceptualize their sexuality if they don't have a word to describe what they're doing," says Khayatt. "Some women don't see their physical relations with other women as important. The important thing is the relation with a man. Some wouldn't conceive anything they do outside of men as sexual." In other Muslim countries in the past, women considered it their duty to prepare girls for marriage in this way.

    The huge majority of lesbians in Egypt get married. A small number of upper class lesbians don't, but are seen as "decadent," she adds. Middle and upper class Egyptian women have words to describe their same-sex relations because they know the English words, but peasant or working class, illiterate women do not.

    Lesbian relations in both upper and lower classes are quite normal, she says. But, once married, upper class women have to carry out relations discreetly. Says Khayatt, "You can get as much sexual practice as you want, as long as you fulfil your duty and marry and have kids."