Every parent is curious about what their kids learn in sex education class.

But when Michigan mom Alice Dreger found out that abstinence was the subject of her son's upcoming lesson, she was so curious, she decided to go back to school,

With her son's permission - and the school's -- she sat in the back of the class last week.

"I offered to go and he wanted me to go. There have been many cases in his school career where something's been going on and I've asked him do you want me to go. He's never said yes before," she tells co-host Carol Off.

The medical humanities and bioethics professor teaches at Northwestern University and does research on sex. The plan was to sit quietly in the back while the state-required course on abstinence was taught.

But that all changed when the lesson started.

"They were teaching the kids through a game....that one out of six times a man and woman have intercourse, that the condom will fail and the woman will get pregnant...and they were handed a paper baby." Eventually, the whole class had babies.

"Almost from the beginning...It was clear to me what they were going to impart in that classroom was the story of how you can abstain from sex and have a delightful life or you can not abstain and have a terrible life and that's exactly what went on to happen."

A guest speaker told the class he only found happiness after he met a girl who led an "abstinence lifestyle."

"The lesson was...that when you meet a girl who says no that's the woman you want, basically slut-shaming the girls who might say yes," Dreger says.

She says she's not opposed to teaching teens the value of waiting to have sex or how to prevent pregnancy, but it has to be done with facts and without shame.

"If they do end up with an unwanted pregnancy or end up with a disease, they need to be able to talk to an adult about that right away or get help right away," she says.

She admits that when the class was over she had choice words for the educators. She says she swore and yelled because of her "shock" at what they had told the class.

"I regret that mostly because the school district has used that as an excuse to not let me back in the school because I used the 'f- word' in front of students."

But she says she's had support from many parents and their kids.

"I found out some students in the school had already been organizing to change the state legislation to stop this teaching being required."

And there's an odd overlap between her personal life and her professional life. Her new book,Galileo's Middle Finger,which she describes as being about social activism, and science, was just reviewed in the New York times

"One of the lines….says that Dreger shows that sex will get you into trouble. Wow, what a funny line to be reading today given what happened yesterday!" she says in reference to her son's class.