When it comes to sex, there’s so much misinformation floating around that it’s hard to know what—and what not—to believe. Here are the cold hard facts about 11 lies you’ve been told about sex. 

LIE 1: AN INTACT HYMEN IS A SIGN OF VIRGINITY. 

A woman can break her hymen by having sex—or by doing gymnastics, horseback riding, or performing any number of other physical activities. Or, she could have been born without one. Women can also have an intact hymen and still be sexually active. The thin, flexible membrane reveals nothing about a woman’s virginity; in fact, experts say its importance is little more than a social construct. 

LIE 2: MEN WITH BIG FEET ARE BIG … EVERYWHERE. 

The average male penis size is five inches—and studies show that there’s little correlation between shoe size and, well, your size.

LIE 3: SOME FORMS OF SEX ARE SAFER THAN OTHERS. 

You can’t get pregnant from oral sex, but that doesn’t mean you can’t contract sexually transmitted diseases from the act. Any time you refrain from using a barrier method of contraception (condoms, dental dams, etc.), you’re at risk for the same scary infections you tend to associate solely with intercourse. 

LIE 4: ONLY YOUNG MEN DEAL WITH PREMATURE EJACULATION. 

It’s commonly viewed as a “young man’s problem,” but premature ejaculation is actually a chronic condition that affects individuals of all ages, with no increase or decrease in rates as you age. 

LIE 5: THE PILL MAKES YOU GAIN WEIGHT. 

Convinced your birth control made you put on a few extra pounds? Think again. According to doctors, there’s little scientific evidence that the pill causes weight gain. Due to a variety of factors, women tend to get heavier with age—a phenomenon they sometimes (wrongly) attribute to oral contraceptives. 

LIE 6: MEN THINK ABOUT SEX ALL THE TIME.

A recent study found that half of men think about sex less than 19 times a day—which is about the same frequency that men think about food. 

LIE 7: SEX BURNS A LOT OF CALORIES. 

It might feel like a strenuous aerobic workout, but scientists say that a 150-pound man burns a paltry 3.5 calories per minute during sex. If this number sounds like a lot, keep the following fact in mind: He burns one-third that amount of energy watching TV.

LIE 8: ONLY MEN HAVE WET DREAMS. 

One prominent survey found that nearly 40 percent of women have woken up from a vivid dream due to an orgasm.  

LIE 9: MEN DON’T NEED THE HPV VACCINE. 

The human papillomavirus (HPV) can cause cervical cancer in women. But did you know it can also cause penile cancer in men, and oral and anal cancers in women and men? HPV is so common that experts recommend young girls and boys alike receive the HPV vaccine (even though the vaccine is heavily marketed toward women). The vaccine is safe, and it helps protect both genders from future exposure. 

LIE 10: WOMEN DON’T LOOK AT PORNOGRAPHY. 

Past media surveys have found that one in three visitors to adult websites are, in fact, female. 

LIE 11: WOMEN ARE MORE SEXUALLY FLUID THAN MEN.

One national study showed that both men and women engage in sexual activity with partners of the same sex at about the same rates—and not all of them self-identify as gay, lesbian, or bisexual.