That's the question being asked in China over a series of textbooks aimed at children ages 6 to 13.
Published by Beijing Normal University, and the product of over nine years of testing, the books are currently in use in 18 elementary schools in the Chinese capital, and are being sold in bookshops.
Despite being in some schools for almost a decade, the books attracted controversy this week after a parent posted pictures from them on Weibo, China's answer to Twitter.
The user, who said she was from Hangzhou in China's southern Zhejiang province, said even she was too shy to read the content and criticized it for being too graphic and said her child's school had restricted access to the books since she complained to them.
The photos of the textbooks went viral on Weibo with comments both criticizing and defending their use.
What's the problem?
The textbooks cover a variety of sex and relationship issues, including reproduction, sexual abuse, gender issues, homosexuality and safer sex.
They also feature cartoon illustrations of male and female genitalia, penis-in-vagina penetration and menstruation.
While all of this may seem very normal to some readers, it's a big step forward for China, which has long been criticized for lagging behind
when it comes to sex education.
Jing Jun, a professor of sociology at Beijing's Tsinghua University, told CNN last year that many of his students had not received any sex education until they entered their first year of university.
In 2015, there were 115,000 new HIV infections in China
, according to China's National Center for STD/AIDS Prevention and Control (NCHHSTP). Of those, 17,000, or 14.7%, were in the 15-24 age group.
While the overall figure is fairly low compared to China's massive population, the NCHHSTP estimate the annual growth rate among young people to be 35%.
China also has a very high abortion rate, which analysts have linked to lack of knowledge about other means of contraception.
Backlash and support
After photos of the textbooks went viral on Weibo this month, some people commented to say the content was inappropriate for young children, comparing it to "cartoon porn" and warning that kids may attempt to copy what they saw in the images.
Others, including the publisher, stepped in to defend the books.
"The textbooks are rigorously designed, tested, revised and checked. We have consulted with parents, students and teachers throughout the process," Beijing Normal University said in a statement.
"The need for sex education as well as child sexual development is hugely neglected (in China), as there is a lack of sex education in both family and school."