From Mahmood v. McKnight (D. Md.), the quick factual summary (the opinion is long, so, as usual, I've had to excerpt heavily):
In this lawsuit, parents whose elementary-aged children attend Montgomery County Public Schools ("MCPS") seek the ability to opt their children out of reading and discussion of books with lesbian, gay, bisexual, transgender, and queer characters because the books' messages contradict their sincerely held religious beliefs about marriage, human sexuality, and gender. Last school year, MCPS incorporated into its English language arts curriculum a collection of storybooks featuring LGBTQ characters (the "storybooks" or "books") in an effort to reflect the diversity of the school community.
Initially, parents could opt their children out of reading and instruction involving the books, as they could with other parts of the curriculum. In March of this year, the defendants—the Montgomery County Board of Education, the MCPS superintendent, and the elected board members (collectively, the "School Board")—announced that parents no longer would receive advance notice of when the storybooks would be read or be able opt their children out. Following the announcement, three families of diverse faiths filed suit against the School Board ….
This didn't unconstitutionally burden the parents' or students' Free Exercise Clause rights, the court held:
