Two couples who say a suburban school district undermined their parental rights by giving out and reading storybooks with gay themes without telling them first have filed a federal lawsuit against school officials.

The couples claim the officials broke state law, violated their civil rights, and were trying to teach their children about a lifestyle they consider immoral.

Lexington school superintendent Paul Ash said the schools have no agenda and have done nothing illegal.

Last month, Joseph and Robin Wirthlin objected when a teacher read a storybook about two princes who fall in love to their son's second grade class without notifying them.

David Parker was jailed last year after he refused to leave a school when officials declined to exclude his 6-year-old son from discussions of gay parents. Parker initially complained after his son brought home a "diversity book bag" with a book that depicted a gay family.

Their attorney, Jeffrey Denner, said Lexington violated the rights of privacy and freedom of religion of his clients — all identified as devout Christians in the lawsuit — by unilaterally deciding how and when lessons about gay marriage will be taught.

"Parents need to be the ones to determine when it is introduced and how it is introduced," said Parker.

Denner said the school is ignoring a state requirement to notify parents when such topics are discussed so they can remove their children from class if they want.

The school has argued that the state's "opt-out" law requires schools only to inform parents about class content when sex education or human sexuality is the primary focus.

Ash said it would be impossible to notify parents every time such issues come up, because in some cases, it isn't planned.

"In Massachusetts, gays have equal rights," Ash said. "We have gay marriage. Our kids see it, it's part of our overall curriculum. We talking about what kids see in today's world."

The lawsuit, filed by David and Tonia Parker and the Wirthlins, names Ash, the town, school committee members, and other school officials. It seeks unspecified compensatory and punitive damages.