Think you've got him all figured out below the belt? Think again. Our man-atomy review is filled with little-known facts that will lead to big pleasure for him — and guaranteed satisfaction for you
The Big Fella
The penis is far more complex than the fresh Polish sausage it resembles. At the top is the nerve-packed, helmet-shaped head called the glans. The thick, rounded rim of the glans is the corona. Right below the point where the corona curves up (on the side of the penis facing you when it's, er, happy), you'll find an ultrasensitive ridge called the frenulum. This stretchy band of tissue is attached to the foreskin of an uncircumcised penis. Your man sports a tailored turtleneck? His frenulum's only function is to register good vibes.
Moving down, the bulk of the shaft is made up of corpora cavernosa, two columns of spongy tissue that fill with blood to produce an erection. Similar tissue composes the corpus spongiosum, which surrounds theurethra, aka the handy hose that transports urine and sperm from their respective sources to the opening at the tip of the head.
A couple more fun phallus facts:
"There are three kinds of erections," says Karen Boyle, M.D., director of reproductive medicine and surgery at the Brady Urological Institute at Johns Hopkins Hospital in Baltimore. Reflexogenic occur from actual contact, psychogenic ones result from fantasy or audiovisual stimulation, and nocturnal erections take place (duh) at night.
The average erect penis ranges in length from 5.5 to 6.2 inches. To make your man's penis seem bigger, get on top, tilt your pelvis in the direction that feels most pleasurable, and push down for greater depth, suggests sexuality educator Amy Levine, founder of sexedsolutions.com. 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.
The sperm and testosterone factories known as testicles roll around in that wrinkly sack called the scrotum. When it comes to balls, size matters -- to a point. "In general, the larger a man's testicles, the higher his testosterone level and the more sperm he'll produce," says Harry Fisch, M.D., director of the male reproductive center at New York-Presbyterian Hospital/Columbia University Medical Center and author of The Male Biological Clock. But as long as they're walnut size or bigger, they should get the job done. To boost your partner's reproductive health (and maintain his dignity), tell him to avoid super-tight spandex and lengthy Jacuzzi sessions -- too much restriction and/or heat throws a wrench in the works.
On the pleasuring front, be gentle. "It's more about stimulating the scrotal skin than the actual testicles," Kerner says. To send a shiver of deep and lasting gratitude through his body, locate the raphe, the central line that runs down the middle of his scrotal sack, and trace it with your finger or tongue.
The nut tugger
Surrounding the sac of each testicle is a thin layer of brawny flesh called thecremasteric muscle. Designed to help keep his cojones at the ideal sperm-producing temperature, this sucker draws the testes toward the body when it's cold and lowers them when it's hot. It's also responsible for what's known as the cremasteric reflex. Like your lower leg popping up when the doc taps your knee, the cremasteric contracts when you stimulate the insides of our upper thighs. It doesn't necessarily turn us on (unless you're holding a little mallet and dressed as a nurse), but it does let you play with our goods in a fun new way.
The Space Between
Inching farther down, the perineum is that smooth runway of flesh between the scrotum and the anus. In spite of the small army of nerve endings stationed there, not all of us want this border crossed. To gauge your guy's interest, go slow. During foreplay or sex, begin by gently cupping his testicles. Slide your fingers down and graze 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...
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 (see below) 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. So, um, stick to the space between (see above) unless we say otherwise.
The Baby Makers
Though dispensed in a few enthusiastic seconds by the penis, it takes about 2 1/2 months to cook up the hundreds of millions of sperm in the average ejaculation. After sperm form in the testicles, they migrate up to theepididymis to continue developing, says Stephen Jones, M.D., vice-chairman of the Glickman Urological and Kidney Institute at the Cleveland Clinic and author of Overcoming Impotence. Fully formed sperm then travel through the vas deferens -- the long, thin tube that gets snipped during a vasectomy -- and swing by the seminal vesicles, where they mix with a fluid that helps form semen. 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, though, the pea-size Cowper's glands near the base of the penis clear the hallway -- they secrete a substance to flush urinary residue from the urethra. And finally, after all that endless preparation, comes the euphoric moment we're always waiting for.