Alice Dreger, a professor of medical humanities and bioethics at Northwestern University, has written about the importance of honesty in sex education. So when she learned that her son's health class was abstinence-only, she went to see what they were being taught.

Her son let her join him in class, where she sat at the back of the room and live-tweeted the proceedings:

The whole lesson here is "sex is part of a terrible lifestyle. Drugs, unemployment, failure to finish school -- sex is part of the disaster" — Alice Dreger (@AliceDreger) April 15, 2015

"You'll find a good girl. If you find one that says 'no,' that's the one you want." HE ACTUALLY JUST SAID THAT. — Alice Dreger (@AliceDreger) April 15, 2015

Now the woman is up. "Sometimes condoms fail." — Alice Dreger (@AliceDreger) April 15, 2015

She's now telling story of condom box in which EVERY SINGLE CONDOM HAD A HOLE. — Alice Dreger (@AliceDreger) April 15, 2015

"We are going to roll this dice 8 times. Every time your number comes up, in pretend your condom failed and you get a paper baby." JESUS!!! — Alice Dreger (@AliceDreger) April 15, 2015

Paper babies are being handed out to EVERYONE. They have ALL HAD CONDOM FAILURE AND THE WHOLE CLASS IS PREGNANT. — Alice Dreger (@AliceDreger) April 15, 2015

(There's much more of this on Dreger's Twitter timeline.)

The federal government spent $1.3 billion on abstinence-only sex education between 1996 and 2009, even though a federally funded study in 2007 found the approach had no effect on when students started having sex, whether they had safe sex, or how many partners they had.

Congress just voted to extend funding for the program through 2017.

Read more: 20 charts that explain how American kids learn about sex