This is what HIV activists and sex educators call "bullshit." Here's an alarming fact: Most sexually active high school students in the United States know little to nothing about HIV. Many have never experienced a sex education class. If they have, their class was likely focused on abstinence as the "best" health approach (it is, in fact, the least effective. Their teachers likely excluded -- and may have even prohibited -- discussion about non-heterosexual sex or contraceptives.
Since we do not inform teens about adequate safe and safer sex practices, which include frequent testing, condoms, and contraceptives, it's absurd and irresponsible to expect young people to make informed sex decisions. Like other items on this list, this myth is thinly veiled sex shaming, one built on generations of Christian sex policing and purity myths.
Sex-positivity is essential for public health. Let's say that, in a best-case scenario, a sexually active student learns about clinics and discovers the necessity of frequent testing without any problems. Even with that knowledge, humans still get horny. We make decisions in the heat of the moment, and sexual social spaces revolve around alcohol and other substances that make it nearly impossible to make flawless decisions every time.
Wanting sex doesn't make you irresponsible. It just makes you human. The fact is, sexual experiences can result in HIV and other sexually transmitted infections. Instead of policing behavior, shaming human sexuality, and setting impossible expectations, we should make sexual information easily accessible and foster a culture that welcomes discussion about sex and sexual health.