What's a dental dam? And who uses them?
A dental dam is a square piece of stretchy latex or a similar material. They're used to cover a woman's genitals when she receives oral sex. Oral sex is a sexual act where someone's mouth touches the other person's genitals. Genitals are the sexual or reproductive organs that are on the outside of the body (the testicles and penis of males; and the labia, clitoris, and vagina of females). A dental dam helps prevent the spread of STDs (sexually transmitted diseases).
If a guy is receiving oral sex, he should wear a condom to prevent the spread of STDs.
You can buy dental dams online and at some drugstores. Some sexual health clinics have them available for free.