On “Last Week Tonight,” John Oliver takes on sex ed in America.

Back-to-school season is here, and John Oliver of HBO’s Last Week Tonight recorded a must-see segment on the sorry state of sex education in America.

The 21-minute segment spells out the many reasons sex-ed programs fail our kids—for example, only 13 states require that sex-ed information be medically accurate—but Oliver gets the point across with wit and humor.

The show includes examples of real-life sex-ed public service announcements (PSAs) and snippets of lectures from sex-ed teachers who instill shame and stigma in addition to misinformation. It’s as if, Oliver notes, the instructors are warning kids that “God is watching you masturbate, and the fluids coming out of your genitals are actually his tears. You’re making him sad.”

“Sex ed, when done well, can do so much good,” Oliver says. “But when done badly, it can do so much harm.”

At the segment’s end, Oliver enlists the help of Laverne Cox, Megan Mullally, Nick Offerman and several other comedy stars to re-create one of the sex-ed PSAs. The result is not just hilarious—it’s actually informative.

Too bad our nation’s students don’t get such good schooling.

Last year, a POZ cover story explored the connections between sex ed and HIV. To read that feature, titled “Hot & Bothered,” click here.