Desire sometimes ratchets upward soon after hot sex.

Does "the more you scratch, the more you itch" sometimes apply to sexual jollies? Is the reverse true? Intriguingly, the Chinese noticed a "ratcheting up of sexual desire after orgasm" thousands of years ago. Men today do too:

I sometimes feel hornier in the days following orgasm. At such times, I also have strong feelings of attraction for other women (even though I'd never want to have sex with anyone other than my partner).—Tom

My new girlfriend and I got each other off, and now, a day or two later, I'm definitely noticing powerful urges to masturbate and look at porn again (after three months porn-free). It seems so contradictory that our heavy petting would trigger this, but it's happening. I'm masturbating more and I even looked at homemade porn yesterday.

After spending eight months in Asia studying abroad and holding strong boundaries, I came back to the States ready for MEN!

Gorgeous men abound here, and I had no trouble connecting with several lovers in the first few months. After many years of being stuck in the orgasm cycle, I was tired of it. I wondered how would Karezza (being sexually intimate without orgasm) work for singles?

Monkeys in enduring relationships show a surprising correspondence in their levels of oxytocin, a key behavioral hormone, according to research published online June 28 in the journal Hormones and Behavior.

While measuring oxytocin in the urine of 14 pairs of cotton-top tamarins,Charles Snowdon, a University of Wisconsin-Madison professor of psychology, observed a wide range of hormone levels.

But he also saw a striking correspondence among the couples: When one mate had a high level of oxytocin, so did the other, and vice versa. Furthermore, partners with a high level of oxytocin performed correspondingly more cuddling, grooming and sex, while those with low levels of oxytocin spent less time on these relationship-building activities.

Will an orgasm a day really keep the doctor away?

Several years ago, men began showing up in my website's forum struggling to end compulsive porn use. Gradually, they worked out that a period of abstinence often helps reboot their brains. (Initially, their sexual arousal is so tightly wired to porn images and flashbacks that foregoing orgasm for a time can speed re-wiring and stave off binges).

Discussions naturally arose about whether frequent ejaculation is needed for health reasons. Surprisingly, there is no consensus on the answer. There is, however, a wide gap between popular lore and the views of most reproductive health experts.

Overcoming The Monogamy Challenge

Has your sex life become so dissatisfying that you feel restless with your marriage, or even resentful of your spouse?

Marnia Robinson joins us to take a look at the science behind why steamy romance is destined to fade, what that means for the future of marriage, as well as to share some of her 31 tips for reengaging sexually with your spouse.

It's an unsettling fact that by age 11 most boys have been subjected to pornographic images. Yet few materials on the subject address such a youthful audience. If you're a parent, it can be surprisingly difficult to find a good way to discuss pornography. You don't want your child to see sex as "forbidden" or "dirty," but no matter how sex-positive you are, you sense that porn isn't the best way to gain a sex education.

"Financiers take too many risks; scientists do not take enough." --Seth Roberts

When your appetite changes, your perception changes. Think about how uninviting that fifth slice of pizza is compared with that delectable first slice. Recent brain research is revealing a disturbing phenomenon: intense natural stimuli can interfere with our brain’s normal appetite satiation mechanism. By numbing the pleasure response of the brain, such stimuli can make pleasures less satisfying. The effects linger for weeks. The result is less overall enjoyment and contentment, even though the superstimuli continue to register as especially “valuable.”

Could this sneaky primitive mechanism also be at play in our love lives? We can’t say, because it hasn’t been studied.