The Supreme Court on Friday backed a group of religious parents who want to opt their elementary school children out of engaging with LGBTQ books in the classroom, another major legal win for religious interests at the conservative high court.

In the latest decision blurring the line that once clearly separated secular education from religious belief, the court said that a suburban school district in Washington, DC, burdened parents’ First Amendment rights by refusing to allow them to pull their children from the classroom when the books are used.

Justice Samuel Alito wrote the opinion for the 6-3 conservative majority.

“The board’s introduction of the ‘LGBTQ+-inclusive’ storybooks, along with its decision to withhold opt outs, places an unconstitutional burden on the parents’ rights to the free exercise of their religion,” Alito wrote for the majority. “The parents have therefore shown that they are likely to succeed in their free exercise claims.”