Guys might want to consider using the recently released oral contraceptive pills instead of condoms, since psychologist Gordon G. Gallup believes that women actually like semen. Findings say that women who engage in sexual activities without the bother of condoms are less likely to be depressed or commit suicide. If they often have sex, however, they get increasingly depressed as time goes by without getting laid.

This led Gallup to think that semen actually has powerful - and potentially addictive - mood-altering chemicals which the vagina's walls absorb along with testosterone, estrogen, prolactin, luteinizing hormone, and prostaglandins.

Semen may also cause chemical dependency like marijuana does. Gallup found out after a survey of 293 college women, that those who don't use condoms in sex tend to get a new partner as soon as the last disappears to get back into action.

It's possible that those who choose not to use condoms are less likely to be depressed anyway, but studies beg to differ. The behavior involved in making such decision is sexual-risk taking, something that is not related at all to lower rates of depression.

One of the many mysteries of men, such as their preoccupation with girls' heinies and the presence of much energy in their groinal area so early in the morning, is the phenomenon of dozing off right after sex. A lot of women are baffled as to why this happens, but rest assured, girls - it's not that the guy you slept with found you boring or fat. Men are just biologically programmed that way.

Author Melinda Wenner of Scienceline, a project of New York University's Science, Health and Environmental Reporting Program names factors that make men doze off post-coitus. First, and very obviously, is that sex usually happens at night in bed. Next, a study of their brains found out that in order for men to reach orgasm, they must let go of all anxiety and fear, which is kind of relaxing and thus leads to sleep.

The chemicals released by the brain during a man's climax also promote sleepiness after intercourse. During ejaculation, the brain releases the chemicals norepinephrine, serotonin, oxytocin, vasopressin, nitric oxide (NO), and the hormone prolactin. Prolactin is linked to the feeling of sexual satisfaction. Studies reveal that the hormone is linked to sleep. Releasing prolactin during orgasm causes men to feel sleepy, albeit satisfied.

For some unknown reason, though, prolactin levels are higher in men after sexual intercourse than after masturbation. So relax. He may basically ignore you after doing the deed, but that doesn't mean that he doesn't like you. Men cannot live on porn alone.