I thought writing about my below-the-belt anatomy would be easy. After all, I've had access to the equipment for 29 years. But the first expert told me something I didn't know: "There's a difference between ejaculation and orgasm," says Dr Edward Ratush, creator of Lovelifemd.com.

There is? Three kinds of erections? Guys faking it? Once my head stopped spinning, I put together this explanatory guide to a man's twig and berries. Get ready to teach the guy in your life a thing or two about what he's made of.


The big fella
The penis is more complex than the raw snag it resembles.

"The upper areas near the head respond to friction," says Dr Ian Kerner, sex therapist and author of He Comes Next ($25.50, HarperCollins). "The lower parts near the base respond to pressure."

To provide the perfect combo (not that you asked) tightly encircle the base of the penis with your fingers to restrict blood flow out of the shaft, making his erection harder and delaying orgasm. Supply friction at the head with your mouth or other hand and - ta-da! - he'll take out the rubbish for a month.


Fun phallus facts
"There's more than one kindof erection," says Dr Margaret Redelman, president of the Australian Society
of Sexuality Educators, Researchers and Therapists.

Reflexogenic erections are from actual contact - "the brain isn't necessarily turned on," says Dr Redelman. Psychogenic ones result from audiovisual stimulation or fantasy, and the two types usually combine while we're having sex. Then there are nocturnal erections, which occur two to six times a night due to biorhythms that keep our body's organs in working order while we sleep.


Does size matter?
In Australia, the average erect penis is 15.3cm long. To make your partner's seem longer, put a pillow under his bum when you're on top, tilt your pelvis in the direction that feels most pleasurable, and push down for greater depth, suggests Dr Redelman. Or, in missionary, place your feet on his chest, which will make your vaginal canal feel shorter and better angle you for G-spot stimulation, says Amy Levine, founder of sexedsolutions.com.


The nut tugger
Surrounding the sac of each testicle is a layer of flesh called the cremasteric muscle. It draws the testes towards the body when it's cold and lowers them when it's hot, to keep his boys at the ideal sperm-producing temperature. It's also responsible for what's known as the cremasteric reflex.

Like your leg popping up when the doc taps your knee, the cremasteric contracts when you touch the insides of our upper thighs. It doesn't necessarily turn us on (unless, perhaps, you're dressed as a nurse), but it does let you play with our goods in a fun, new way.


The bit between
Moving further down, the smooth runway of flesh between the scrotum and the anus is the perineum. In spite of the army of nerve endings stationed there, not all of us want this border crossed.

To gauge your bloke's interest, go slow. Begin by gently cupping his testicles. Slide your fingers down and stroke the area, then apply gentle, upward pressure. If he doesn't jump a mile, keep going. Gradually increasing pressure - you can switch from fingertips to knuckles if he's really into it - may indirectly stimulate his prostate gland. Which brings us to...


The G-thing
Tucked just below the bladder is the chestnut-size prostate. This gland's main job is to release a slightly acidic substance that, combined with fluid from the seminal vesicles and sperm, makes semen.

Guys may jet to a very happy place when you stimulate the prostate - some sex experts even refer to it as the male G-spot. That said, to get to it directly, you have to sneak in the back door - not everyone's idea of fun.


The baby makers
Though dispensed in a few seconds, it takes about 2½ months to cook up the hundreds of millions of sperm in the average ejaculation. Sperm form in the testicles, then migrate to the epididymis to continue developing.

When a man nears ejaculation, the prostate adds its own fluid to the semen, which then taxis the sperm through the urethra on its way to the door. Before it exits, the Cowper's glands near the base of the penis secrete a substance to flush urinary residue from the urethra. And finally, after all that preparation, comes the million-dollar moment.