Her reasons? Receipt of another anonymous letter from a young white student, declaring his lust for her in no uncertain terms. He wanted to rip her clothes off and possess her, he said, because she seemed so utterly unattainable. To her astonishment, a Muslim male student had also started whispering suggestive things to her as she walked past, all about how her modesty turned him on.
This is not an isolated case. The veil draws to it and releases all sorts of contradictory meanings and heightened emotions which can shock even those who take the decision to wear it for rational and understandable reasons. After an article I wrote about Muslim women in Bosnia - photographed in hejab - I had five letters from white men telling me how intensely desirable they found women who covered themselves. Interviews on the subject I recently conducted with men in London were equally disturbing.
Although only one of them found the hejab distasteful, and some were hostile to the rise of Islam in Britain, many of the men confessed that there was something challenging and arousing about veiled women. A dashing young designer spoke with some ferocity against "bloody feminists" who had emasculated men and against women who invited men to "take them sexually by exposing everything". What he wanted was one of these demure ladies who seemed so pure and serious and precious.
Another man, ardently obsessed with the Eastern babe fantasy, said it must be like unwrapping a Christmas present. Yet another spoke earnestly about how he desperately wanted a relationship with such a woman because he could be sure that she had not beensleeping around. Haleh Afshar, an Iranian academic and writer, told me how a policeman wrote her a six-page letter begging for pictures of women in veils.
None of this is surprising. The eroticisation of purity has always been part of the Western cultural tradition; conflicting images permeate Eastern life, too. Just as lifting the bride's veil is a quivering moment in Hollywood films, unveiling a (virginal) woman on her wedding night is the emotional high point of most Hindi films. In the more vulgar variety, the heroine will throw off her black robes half way through an awful song to reveal as much as she is allowed by the censors. Pornograph e rs and fashion designers on the subcontinent (mainly in India) also regularly subvert and appropriate the real purpose and significance of the hejab.
The appeal of the forbidden goes back at least to Victorian men such as the explorer Richard Burton, who despised the East but harboured insatiable fantasies about the hidden, assumed sensuality of Islamic women. This was, argues the writer Dr Rana Kabbani, because they wanted possession of something they knew they had no access to; it showed them that however much they were the dominant power, one part of Islamic society would always elude them. Hence the infuriation and the desire.
There is the same schizophrenia now - with some added twists. The French go apoplectic over schoolgirls covering their heads, but excitedly applaud models on Parisian catwalks swirling about in chiffon veils and harem trousers. It is all right to use theveil to titillate the senses and to sell products, but not to protect yourself from male attention. For a society consumed on the one hand by Islamaphobia and by the commercialisation of sex on the other, the hejab is an affront on both counts.
Hence Muslim women's motivation for wearing the hejab - to feel connected to their religious roots, to de-sex themselves in order to be taken seriously, to avoid being molested - is being thwarted.
Yasmine, whose father is Pakistani and mother an English convert to Islam, decided to take on the hejab when she started at university in London. Modesty, she felt, marked her out, got her noticed and respected by her lecturers, especially those who takemore than a professional interest in the female students. She thought it would help to change stereotyped perceptions if she, a veiled Muslim woman, gave up her seat to an old lady, or read (as she does) Aristotle's Poetics on the train, or rode a Harley-Davidson (as she wants to). She was also trying to test people who are not threatened by a "bum skimming skirt" but are petrified by a headscarf which, she sweetly points out, is what Christ's mother is often shown wearing.
But now Yasmine is less sure whether wearing a hejab is possible. Apart from becoming the object of male lust, women like herself become inadvertently identified with militant Islamic groups.
The feminist reaction to the hejab is caught in a similar labyrinth. The majority of white feminists dogmatically see it as a sign of male oppression, even though increasing numbers of Muslim women in Europe are actually choosing to take it on. Some Muslim feminists agree with this view and argue (quite plausibly) that the choice is often the result of brainwashing or disenchantment with the West. Others reject these views as sophistry. Choice, they say is what feminism ought to be about - even when thechoices are unacceptable to other feminists. There are independent women who do find their sense of self confirmed by the hejab.
But then how do you distinguish between those who have freely made the decision and those who are forced by families or young male militants to wear a veil? What about the Algerian women who are apparently being attacked and even killed for not wearing the hejab?
And what about those who have changed their minds? Afshar, in her study of three generations of Muslim women in Bradford, finds that many of the same young women who opted for the hejab when emotions were high after the Rushdie crisis, now feel they havebecome victims of fundamentalism: if they don't wear a hejab, their brothers force them to.
Meanwhile, many Iranian women who took on the veil when they were part of the revolution are now resisting it. Earlier this year, an Iranian child psychiatrist, Homa Darabi, set her veil alight and burnt herself to death in protest at the renewed subjugation of women in Iran. These women are not like the middle-class women of previous generations who discarded seclusion and the hejab in order to join what they thought was the progressive Western world. They took on the hejab for radical reasons and to reject what their mothers had done. Now they find they are being denied basic freedoms.
Is it right, then, that European Muslim women who have taken on the hejab should ignore these grotesque injustices just because acknowledging them would interfere with the clarity of their own motives?
There are other reasons, say Kabbani, Afshar and others, why the whole issue needs to be re-thought. The hejab is not as strictly Islamic as it is professed to be. It was a practice taken on by middle-class Muslim women in the seventh century partly because that was the tradition of the (Christian) Byzantines, who wanted to keep themselves aloof from the masses.
Michelle Messaoudi, a French convert, says that the Koran asks women simply to dress modestly and this can be interpreted creatively: by wearing trousers and a loose scarf, for example. Thus Muslim women can achieve a definable identity while remaining part of the occidental world - enabling them to move into desirable careers and take opportunities that might otherwise be denied them. Prominent Muslim women such as the Channel4 newscasters Zeinab Badawi and Shanaz Pakravan seem to be doing just that.
The hejab has proved to be an important cultural and political touchstone. It has revealed the limits (and hypocrisy) of liberal tolerance and feminist understanding. It shows that even liberal democracies like France are capable of religious persecution. It has given dignity and a sense of belonging to European Muslims - including, these days, those in Bosnia, where young women have started wearing veils for the first time ever.
It is an important reminder that not everyone is falling over themselves to join the materialistic, individualistic circus of the West and that people do need faith and religion. And it is also true that the hejab liberates women from the agony of livingup to the dictates of fashion, and challenges the idea, popularised by Madonna, that a woman becomes more free, the more she flaunts herself. Some women feel it is empowering to be in a position to observe men whilst keeping themselves hidden.
But despite all this, the hejab is now so invested with different (and sometimes appalling) connotations that it is not possible to extract the meaning you wish to promote and hope the world will somehow understand.
Even more important, many of those involved in the struggles to negotiate a legitimate place for Islam in the new Europe feel that the hejab is becoming a damaging distraction, a crude emblem that polarises people and helps to justify - as in France - the exclusion and maltreatment of Muslims.