A Michigan high school teacher would not allow a student with two mothers to write about same-sex marriage for a class assignment.

Destiney McDermitt, 16, a junior at Hill McCloy High School in Montrose, about 70 miles northwest of Detroit, was instructed by an English teacher on Feb. 7 to pick a topic she felt strongly about and argue either for or against it as part of an assignment titled "Taking a Stand," she and her mother Angela McDermitt-Jackson told NBC News on Tuesday.

McDermitt-Jackson said the teacher told her daughter that she could not write about same-sex marriage because the topic might offend someone in the class.

"My daughter actually asked the teacher to ask the class if it would offend anybody," McDermitt-Jackson said, recalling the account of events as told to her by Destiney. "At which point, the teacher told her, 'I don't want to hear about it, I don't want to read about it and I am the one who has to grade it.'"

Destiney then texted her mothers from class and told them what was going on, McDermitt-Jackson said.

"She was upset and offended, and she felt it was very inappropriate," McDermitt-Jackson said.

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McDermitt-Jackson said that later that day, she and Destiney's other mother, Christine Jackson, went to the school and met with the principal and the superintendent.

"They both agreed it was absolutely wrong and was unacceptable," she said.

Administrators took a statement from Destiney and other students in the classroom at the time and vowed to conduct an investigation, McDermitt-Jackson said.

Linden Moore, superintendent of Montrose Community Schools, said in a statement Friday that "the teacher attempted to avoid disruption and controversy by limiting the topics that students could choose for a writing assignment."

"Unfortunately, although well-intentioned, the teacher was too restrictive," the statement said. "We have spoken to the teacher and all of our staff about valuing opinions, beliefs, and rights of all of our students."

The superintendent said this has been "a learning opportunity for everyone involved." Moore did not immediately return a request for comment Tuesday.

McDermitt-Jackson said she is unsatisfied with the school district's response.

"They completely failed not only my daughter, but they failed all of us," she said. "They did not handle this appropriately."

She said she filed a complaint last week with the American Civil Liberties Union of Michigan because she believes her daughter was discriminated against and her right to freedom of speech had been violated.

Ann Mullen, a spokeswoman for the ACLU of Michigan, declined to comment Tuesday, saying: "We do not disclose if or when we are contacted by a potential client."

McDermitt-Jackson said she does not believe the teacher, whom the district is not naming, "has any business teaching in a public school district."

Destiney has since been switched out of the teacher's class, McDermitt-Jackson said.