Sex can be surprising and confusing, even for the most experienced among us. From the mysterious female ejaculation to the one piece of clothing that can make you orgasm faster, here are Medical Daily’s top 20 most surprising sex facts for both men and women.

1. Infertility Is Far More Common Than You May Think

Infertility can be devastating, but research suggests it’s far more common than you may think. For example, a study published earlier this year found that infertility impacts one in eight women, and the Centers for Disease Control and Prevention found that about six percent of married women aged 15 to 44 are still unable to get pregnant after a year of unprotected sex, and about 12 percent of women have difficulty carrying a pregnancy to full term.

Read: Have A Better Sex Life With 7 Science-Backed Tips

2. Men Have A G-Spot

Men have an area on their body similar to the sought after female “g-spot” which, when stimulated, can cause extreme pleasure. The area is known as the prostate, and is located right under his bladder, Cosmopolitan reported. It can be reached by placing a finger inside of his anus and moving it in a circular motion.

3. Women Think About Sex….A lot

Society may make women out to be dainty flowers who wouldn’t dare have sexy thoughts on their own, but in reality, they think about sex a lot and would like to have more of it. For example, one recent survey found that about 53 percent of women were not having as much sex as they would like, and nearly 75 percent of women involved in the survey expressed a desire to make love at least three times a week.

4. Simultaneous Orgasms Are Extremely Rare

Orgasming at the same time as your partner is so rare that most individuals will never experience this in their lifetime. In fact, orgasming at all should be considered an achievement, especially for women: Jezebel reported that roughly 75 percent of men in relationships always have an orgasm with their partner, compared to 30 percent of women.

5. Average Penis Is 5.57 Inches Long

Asking a man his penis size may be a personal question, but chances are it’s around 5.57 inches when erect. According to a study published in the Journal of Sexual Medicine, this is the average penis, although there are always exceptions to this rule.

6. Sex Can Improve Memory In Women

A recent study found that frequent “penis in vagina” sex can also help improve a woman’s ability to remember words and phrases. It does this by increasing the blood flow to the hippocampal region of the brain, and although the same can be accomplished via any aerobic activity, it’s far to fun to do with sex.

7. Men Are Either Growers Or Showers

According to a survey taken by Men’s Health, 79 percent of men have growers, meaning their penis looks bigger when erect, while 21 percent reported to be “showers” with penises that don't grow much in size after erection.

8. Oral Sex Can Make A Penis Longer

Strangely, one study found that men’s self-reported penis size was actually larger when they measured their penises following oral sex, versus after masturbating, although it's not entirely clear why.

9. Sperm Is Fast

Though sperm might look quite stationary outside of the body, once inside of a woman, they can swim pretty fast. According to The Naked Scientist, sperm can travel up to 5 mm per minute, which, if scaled up to size, would be equivalent to a salmon swimming 500 miles per hour or a whale swimming 15,000 miles per hour. Ejaculate is even faster, coming at a reported 28 miles per hour.

10. Apples Are Aphrodisiacs

We’ve all heard of aphrodisiacs such as strawberries and oysters helping to put men and women in the mood, but what about apples? One 2014 study found that women who ate apples more than once a day reported better self-lubrication and overall sexual function compared to women who ate less than one apple a day.

11. Size Doesn’t Really Matter

The media may emphasize the desire for larger-than-average penises, but most women would like something a bit more fun-sized in their partner. In fact, one study found that women were more likely to cheat on husbands with larger penises because they associated large penises with “pain and discomfort during sex.”

12. Period Sex Is Fun Sex

While taboo, sex on a woman’s period is actually far more common and enjoyable than you may have been led to believe. Though messy, some say the extra lubrication during period sex actually makes it feel better. Make sure you use protection because it’s still possible to get pregnant when on your period.

13. There Are Two Types Of Female Orgasms

While orgasms are pretty straight up for men, with women they are a bit more complicated. In fact, women can have two types of orgasms: vaginal and clitoral. Though both are enjoyable on their own, when done together, the experience can be quite eye-opening.

14. Women Are More Attractive When They Ovulate

Although they are not aware of it, men are subconsciously more attracted to women during their ovulation. In fact, exotic dancers actually earn more money during this week in the month than any other.

15 Have Sex With Socks On

If you’re having trouble reaching an orgasm while having sex, try slipping on a pair of socks. Research has suggested that it’s easier to come when your feet are warm.

See Also:

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10 Surprising Sex Facts About Women