Updated

Think you know sex — the human body and opposite sex?

Test yourself and see if you need to go back to sex school.

Although this test is meant to be fun, all the answers are based in studies and sexual health literature.

Answers are true or false.

1. The size of a flaccid penis is in proportion to its size hard.

Answer: False. You have growers and showers.

2. Tantric sex, where men can orgasm without ejaculating, is impossible.

Answer: False. As a man, you train yourself to ease back right before ejaculating; eventually you’ll be able to orgasm without ejaculating.

3. Women are most aroused and wear the shortest skirts during the middle of their cycle.

Answer: True. This usually occurs around day 10-11, when they are ovulating.

4. The main ingredient in semen is sperm.

Answer: False. Fructose sugar, water, vitamin C, enzymes and protein, phosphate and bicarbonate buffers and zinc.

5. Nipples are erogenous zones for most people.

Answer: False. Some can orgasm with soft touch alone. Some like only one nipple and not another. Some like biting or clamps. Everyone is different.

6. Sperm can live in whirlpools, hot tubs or pools.

Answer: False

7. If you are around a lot of chemicals (home design and construction, as well as marijuana), sperm can get damaged.

Answer: True

8. Ejaculate has a lot of calories.

Answer: False. Actually each teaspoon of ejaculate has about 5 to 7 calories — that is about five baby carrots, one cashew, or one-and-a-half M&Ms.

9. Pheromones are strongest during your workout.

Answer: False. They are strongest an hour after.

10. Women with breast implants have higher rates of personality disorders.

Answer: True

Scoring:

9-10 correct: You are a sexual genius.

8-9 correct: You need some brushing up, but your basics are good.

6-7 correct: You have some serious gaps in your knowledge of sex and health; consider a summer class!

5 or less: Go back to school!

Dear Doc,

My girl says my semen sort of itches, can she be allergic to it?

— Itchy and Scratchy, Indiana

Dear Itchy and Scratchy,

Yup, she may be allergic. It’s called human seminal plasma protein hypersensitivity (SPH). Reactions to contact with semen may include localized pain, itching, redness and swelling, or systemic responses, like hives or trouble breathing.

Most symptoms typically start within 20-30 minutes of contact and can last for hours or days.

— Dr. Belisa

Dr. Belisa Vranich is a psychologist and sex expert. She is the author of three books, including her latest "Get a Grip: Your Two-Week Mental Makeover," which is in stores now. Do you have a "Dear Doc" question? E-mail Dr. Vranich at DrBelisa@gmail.com and check out her Web site at www.drbelisa.com.