Your sexual fantasies: the results are in

One man wants to service soldiers on leave, one woman was taught about multiple orgasms during an episode of The Antiques Roadshow . . . what happened when 10,000 people were asked to share their deepest desires?

When it comes to sex, there's no such thing as a simple question. Even the most basic inquiry soon turns out to be loaded. Most sex surveys start by asking the respondent whether they are male or female. Why not female or male? And what about all the other options - all the people who would describe themselves as neither or both? Why do surveys always ask people what they do with their bodies, instead of asking what they don't - and why not? And how are we to deal with the peculiar fact that most sex exists only in memory; or, these days, on mobile phones.

My latest foray into this minefield - entitled Excuse Me, Would You Mind If I Asked You a Few Personal Questions About Sex? - is currently on display at the Wellcome Collection in London. The installation takes its cue from the pioneering scientists and statisticians whose work is documented in the collection's larger show, The Institute of Sexology: Freud, Stopes, Mead, Masters and Johnson. It basically does what they all did: asks total strangers a lot of embarrassing questions. The idea is that you sit down at the end of the sexology show with a questionnaire, answering whichever of its 25 posers you fancy, then drop your answers into a padlocked box. This gets emptied once a week and a team of readers and myself select some of the most thought-provoking (and of course anonymous) thoughts about the nation's sex life for immediate publication on the gallery walls.