Much as we like to bandy the word around with regard to sexual preferences, a true fetish is considered one without which it is impossible to achieve sexual satisfaction. According to my friend C, my weirdest, most outlandish, kink is my fetish for intelligent men. She considers this irredeemably strange. She can't understand why I need to have my mind fucked before I'm willing to let my body be fucked; why I need words as foreplay before the thought of any other foreplay can be entertained, or how a man who can express an interesting thought in a coherent manner can make me wet - and let's not even get into the way I'm aroused by an extended vocabulary.

The vain other side of the coin is also true, of course: the quickest way into my pants is an admiring comment about my intellect (although additional compliments about body parts won't hurt your chances).

There is an erotic frisson about a skillful mindfuck that is almost as good as the real thing (actually, in some cases it's considerably better than the real thing). The thrill of your mind climbing over the landscape of curves and hollows and nooks and crannies and interesting promontories of another mind is exhilarating. Having your mind probed by an enquiring thought is shiver-inducing. But on a more basic level, there's nothing more anti-climatic than finding yourself bored in bed with a dull man when the fucking stops. Apart from anything else, an intelligent man will apply some basic psychology to work out what else turns you on; he can read between the lines of what you don't say to work out what you want...

The enormous difference between male and female sexual behaviour may be explained, in animals at least, by a tiny organ in the nose rather than by any gender difference in brain circuitry.

So say investigators in the United States, who admit to being stunned by the finding and the implications for the understanding of sexuality.

In a study published by the British journal Nature, the team engineered female lab mice so that the rodents lacked a gene called TRPC2, effectively short-circuiting the so-called vomeronasal organ.

This tiny organ in the nose is packed with receptor cells that pick up pheromones - primitive scents that trigger aggression and sexual responses in land-dwelling vertebrates.

To the scientists' surprise, the mutant female mice behaved like men at a Seventies disco night.

They sniffed and ran after females, flounced their pelvises, mounted and thrust at male mice, issuing ultrasonic squeaks of the kind that males emit to show lurv.

She'd been stood by her desk, showing me something on her screen and bent over slightly to point out something specific. I could see the curve of her arse and firm calfs and I moved forward to see the detail, I was stood behind her, well inside her comfort zone.

Turning around, her eyes met mine and I couldn't decide if it was surprise on her face or a hint of a smile, our faces were mere inches apart and the tension grew steadily.

Then she reached in to kiss me.

This I wasn't expecting. Despite all of the flirting, she'd never said that she was interested.

I responded and I soon had her over a barrel, actually it was her desk, but you get my meaning.

Our bodies slowly moved together, we were still fully clothed but that was my next goal as she dropped her hands and submitted to my will.

I kissed her again and my hands travelled down her torso, undoing her blouse button by button, my lips kissing the newly exposed skin as I fought with the next fastening.

Her blouse hung from her shoulders, her cleavage sat invitingly framed by her bra and a gorged myself on her decolletage while she fought to undo my own shirt, to see my chest...

Sexual preferences are primarily biological in origin. But sexual choice is about preferences and constraints. Raise the price of sex with women and more men will choose to have sex with other men - that's what happens in prisons.

In a remarkable paper, Andrew Francis (a graduate student at the University of Chicago) examines how AIDS has changed sexual choice. With admirable precision, Francis lays out the price of sex:

"...it is thousands of times more likely that a male would get HIV having sex with a man than having sex with a woman. In terms of AIDS-related mortality, the expected cost of having unprotected sex once with a man is almost $2000, while the expected cost of having unprotected sex once with a woman is less than a dollar."

Thus AIDS changes the price of sex, do we observe changes in choice? Francis wants to be careful about causality so he uses a clever instrumental variables approach. He reasons that knowledge of AIDS and thus responsiveness to price is correlated with knowing someone who has AIDS and that knowing someone who has AIDS is exogeneous to other factors influencing sexuality. Unfortunately, it appears that he only has information on whether a relative has AIDS and genetic factors mean exogeneity is unlikely to hold. In fact, we would probably expect that simply knowing someone with AIDS is positively correlated with being homosexual (especially in 1992 when the survey was taken).

This question draws its inspiration from the "Big Mac Index".

What are the historical prices for the services of a prostitute purchased
under the US Dollar, UK Pound, and other world-leading currencies
going back to antiquity? I want to go back at least 2,000 years, so I
think I want whatever were the largest civilisations' currencies in
the middle ages, dark ages, Roman empire, and ancient Greece. I don't
know if it's possible to go back as far as Sumeria. Ancient eastern
civilisations would be nice to have.

The exact item(s) to be priced is probably one act of heterosexual
intercourse, without any overnight cohabitation. But this is possibly
best determined by the researcher. Consistency over time is the main
determinant. The inclusion of prices for other acts of prostitution
would make a better answer, but they are of little value if they are
not measured over a similar length of time.

I am aware that prices vary within the countries, and that various
countries will use one currency. Only one country per currency is
required. Within a country, only one value is required, as it is not
as necessary to achieve high accuracy as it is to identify a trend
over time. An average value may be derived, or failing that, a single
measurement may be acceptable. A good answer will take a sensible
approach, perhaps sampling the largest population center.

The answers can come in a table of numbers, or more likely a bunch of
tables. I don't need graphs. Each table should have at least one
currency, time period, and service price.

An acceptable answer will have some kind of continuity through history
(assuming this is possible), from the Euro to the Romans. Of course I
expect to see currencies begin and end through history, such as the
two or three German ones last century...

Where's the best place to engage in outdoor sex?
Just about anywhere. I've done it in the creek, I've done it on horse blankets. I've done it in the long grass, got thorns in my ass. Hell, once I smoothed out pine needles and threw her down right there. Boy, I tell ya, I've done it all outside. On a horse one time, too. I just had her sit on my lap and got the horse in a trot. Shit, man, it worked real good.

A male friend of mine is having a hard time making his girlfriend come. What's your advice for him?
First of all, he should give her to me. Because, goddamn, I'd lick her cross-eyed.

What's your no-fail cunnilingus technique?
I just do it every way I can. I just love eatin' it and I never stop. There ain't no way you can't do it good. If you're lookin' for advice, I'd say lick her from the asshole on up.

What's a good way to initiate a threesome?
Sweet-talk 'em.

That's all there is to it?
Just tell 'em, "Hey, I can take care of both of you. Oh, you don't believe me? Just try me." That just about ought to do it. But of course, then you got to prove it.

What food should a man eat to ensure his virility?
Plenty of steak and eggs. Make sure that the eggs are runny and the steaks bloody. That'll keep the lead in your pencil.

My girlfriend is afraid to try anal sex. How can I encourage her?
Hmm, that's a tricky one. There was this one time I talked this girl into trying it. She said okay, so I'm lickin' her and lickin' her, I got it all juiced up good. Then I go to put it in. I had her underneath me. I poked her pretty hard, 'cause it wasn't goin' in good. She shot right out of my arms, hit her head on the headboard and said, "That's it." She wouldn't let me do it no more. So I don't know, boy, what can I tell ya? Some of 'em will, some of 'em won't. I guess you just gotta sweet talk 'em.

How would you react if a woman asked to penetrate you with a strap-on?
[looks momentarily confused] Oh! You mean she has a . . . [makes two-handed gesture for penis] Shit, I dunno. I have no idea on that, son. She better worry if I get a hold of that thing first.

Any other words of wisdom?
Well, [crosses arms and looks over yonder] I'd say patience. Boy, I tell you: you know what they say about it being a virtue? Well, it's true. You just got to lick 'er and slick 'er, then broom-grab her 'til she hollers.

1. Elvis Costello "Pump It Up":
Down in the pleasure centers,
Hell bent or heaven sent,
Listen to the propaganda,
Listen to the latest slander.
There's nothing underhand,
That she wouldn't understand.
Pump it up until you can feel it.
Pump it up when you don't really need it.

2. DiVinyls "I Touch Myself":
I don't want anybody else,
And when I think about you I touch myself.
Ooh, ooh, ooh, aah.

3. Cyndi Lauper "She Bop":
Hey, hey, they say I better get a chaperone,
Because I can't stop messin' with the danger zone.
No, I won't worry, and I won't fret,
Ain't no law against it yet.
Oop, she bop, she bop.

4. The Vapors "Turning Japanese":
This I've got your picture, I've got your picture,
I'd like a million of you all round my cell.
I want a doctor to take your picture,
So I can look at you from inside as well.
You've got me turning up and turning down,
And turning in and turning 'round.
I'm turning Japanese, I think I'm turning Japanese.

5. Devo "Praying Hands":
You got your left hand,
You got your right hand,
The left hand's diddling,
While the right hand goes to work.

"Can you pick me up at 8:45" said the text message I received as I was having breakfast. It was the signal I was waiting for to tell me that M's husband had caught his flight and her daughter had gone to school.

We had been looking forward to this day for weeks, if not months. M has a bit of a hang-up about fucking another man while her husband is in the same city! We have to wait until he's gone off on a trip before we can get together for some illicit nookie. This morning was the first time since December that our three diaries were in sync enough that we had a chance.
I arrived at her door just after the appointed time. As soon as the door was closed, she was in my arms. Just being able to feel her warm body next to mine was enough to cause my cock to stir and, when she started to grind her crotch against mine, the bulge in my jeans became even more pronounced. We climbed the stairs to the spare room, my eyes fixed on the undulating globes of her bottom as she lead me up. As we were standing in front of the mirrors, M started pawing at my clothes pulling off my shirt rubbing her hands over my chest, pulling at my belt to free the throbbing object of her desire.

As she sought to free my straining cock from my trousers, I pulled her own t-shirt off and undid her bra. Her nipples hard and perky. She pushed me back onto the bed and pulled off my trousers, my legs dangling over the edge meant that my cock stood up erect, waiting for her. She ran her hands up my thighs, taking my balls in one hand and the shaft of my cock in the other. She had that delightful naughty look on her face as she ran her tongue up my cock, pulling back the foreskin to tickle my head with the tip of her tongue, her hands stroking up and down. I could just lay back and enjoy the sensations coursing through my body...

I've noticed a wonderful trend happening at universities these past few years: projects that integrate sex and technology in innovative ways to improve human health and well-being.

Students interested in how technology and sexuality fit together -- who take technology's role in sexual development for granted -- are naturally drawn to fields like interactive telecommunications, human-computer interaction and affective computing. It's a multidisciplinary movement that inspires collaboration among engineers, artists, psychologists and sociologists -- and in these studies, sex comes first. Tech is merely a catalyst.

Because geeks make great lovers, you have to expect a certain level of practical interest in sex tech. And because this generation grew up with the internet and mobile devices and don't always distinguish between "virtual" and "real" life, they are comfortable with technology as a platform for both physical and emotional intimacy.

They also see value in something we don't generally associate with academia: play.

Jennifer Chowdhury attended the interactive telecommunications program at New York University, where her prototypes drew on her engineering training, her artistic aspirations and her sense of humor. Her master's thesis project, Intimate Controllers, is not explicitly sexual -- but it's not something you would use with your sibling, either.

Intimate Controllers is a set of sensors embedded in underwear that direct the action on a video game. Rather than sit separately on the couch and jam fingers against small plastic buttons, players touch each other to control the game.