BOSTON—Parents who objected to discussions of gay families in their children’s classrooms have taken their case to a federal appeals court.

The 1st U.S. Circuit Court of Appeals heard arguments Dec. 5 in a lawsuit filed by parents who sued after their son brought home a book from kindergarten that depicted different kinds of families, including a gay family.

Another Lexington, Mass., couple joined the suit after a second-grade teacher read the class a fairy tale telling the story of two princes falling in love.

The parents say their rights to religious freedom and to control the upbringing of their children were violated by the school system.

A federal judge dismissed the lawsuit earlier this year, ruling that parents do not have the right to dictate curriculum in public schools.

It’s unclear when the appeals court would issue its ruling in the case.