Even parents in one of the richest, most progressive cities in the nation worry about what their kids are learning about sex.

More than 1,600 parents in Palo Alto, California, have signed a petition to stop their school district’s sex education program until it’s changed. These Silicon Valley parents say they are concerned by descriptions provided to middle school students that describe explicit sexual experiences including masturbation, premarital sex, and the use of sex toys.

The parents’ petition argues the curriculum is seductive rather than educational, and “leads 7th graders to follow the examples of a wrong age group and encourages 12 years olds to try sex for ‘wonderful orgasm.’”

“Are you willing to let your 12 years old learn how to have sex from high schoolers?” the petition asks.

The Palo Alto Unified School District curriculum provided to middle school students includes a range of fictional situations with characters older than the 12-year-old students being taught. Examples range from positive (“I’d had orgasms through masturbation before, but sharing yourself with someone you love and respect was really different and it felt wonderful”) to negative (“I started to cry”).

Some parents were opposed to the use of premarital and homosexual scenarios. One scenario highlighted in the petition describes a sexual relationship between two young women, with one line that reads, “Let’s just say that kisses from guys left me feeling bored, like there was something missing.” Another scenario between two young men, which includes a description of one male’s first sexual experience, reads, “We started kissing, and before I knew it, he was putting on the condom and then we were suddenly having sex.”

Parent Meera Lakhani, one of the petition’s signers, wrote she was appalled by the information given to her children.

“I wouldn’t consider myself a conservative, and I was shocked at the content of the ‘education’. My kids came home confused and scared,” Lakhani wrote. “I cannot believe they disseminated such graphic visuals and information without some parental consent. In a time where teenagers already have much confusion and angst, this education was more harmful than helpful!”

The newly implemented California Healthy Youth Act requires schools to supply comprehensive sex education to all public school students. The state law went into effect January 2016, and for the past year in compliance with the law, Palo Alto middle schoolers have been receiving informational materials and instruction from Health Connected, a local nonprofit that provides a “puberty talk” to 5th grade students and “teen talk” to 7th grade students.

Petition signers hope to halt the current programming and begin the process of selecting a new curriculum that they say better fits the values of Palo Alto parents, but after last week’s school board meeting, school board members say the curriculum won’t change.

Though he admits the roll out of new the sex ed materials was flawed, Board of Education Vice President Ken Dauber said he and the majority of board members stand by the curriculum reviewed and selected by the board. Parents not comfortable with the sex ed curriculum have the option for their child to opt out of the program.

“One of the things that you need to provide [under the state law] is consent education and relationship education,” Dauber told The Daily Beast. “And obviously we independently want our students to be prepared for all of the situations they are going to find themselves so that they are able to make healthy decision about their sexuality.”

Board members and parents in support of the curriculum are left wondering if petitioners against the sex ed program are willing to keep their children uninformed, learning about sex “on the playground or from pornography,” as Dauber described it.

Parent Liza Baskind voiced her support of the current curriculum at last week’s board meeting. Citing statistical data on sexual assault prevention and the vulnerabilities of young children beginning to explore their sexuality, Baskind argued that information about sex, cohersion, consent and to “yes, even learn how to put on a condom” is more crucial than ever.

“If my child is ever in a heated moment in the future and there is an iota of a chance that they will retain this information and prevent an unwanted pregnancy or STI then learning this in the 7th grade will have been worth it,” Baskind said at the meeting and in a public statement posted online.

A statement released by the school board defends its curriculum, saying, “The content was fully vetted by our school principals and our chief academic officers. Realizing that these topics and others may not be aligned with some family values, California Law, PAUSD, and Health Connected all provide the right to opt-out of this unit.”

It’s not just Palo Alto that has a problem: Other school districts have balked at the new curriculum, too. Cambrian School District parents publicly voiced their support in April for the Palo Alto parents’ petition to replace the school’s sex ed curriculum, saying, “We are so sorry for what your children and you all have been put through. Sadly the Cambrian School District and other districts Like Saratoga and Sunnyvale in the South Bay are trying to force this same curriculum on our children with complete disregard for parental input and concerns nor the desire to protect our children with age-appropriate material.”

The school district said in a statement it plans to consider implementation changes to better inform parents in an upcoming meeting, but will not alter the curriculum itself.