A Batman researcher was asked not to mention a gay man in a lecture to school children. Instead, he canceled his talks.

Marc Tyler Nobleman is an author who writes fiction and nonfiction mostly for children and teenagers. In 2012, he published a biography called “Bill the Boy Wonder,” about Bill Finger, who was an anonymous co-writer with Bob Kane in the creation of Batman and Gotham City. That book led to a Netflix documentary (Batman & Bill), and to a street in the Bronx being renamed “Bill Finger Way.”

The Batman researcher was invited by a school in Atlanta to talk about his book, with the aim of inspiring young students to research and write nonfiction. He planned to speak about his research, especially about how he tracked down the descendants of Bill Finger to learn his full story.

Part of that story is that Bill Finger’s late son, Fred Finger, was gay. On August 21, after his first presentation at Sharon Elementary School in suburban Atlanta, he mentioned this fact because it had almost made him miss learning that Fred, who passed at 43 of AIDS, also had a daughter who is still alive today. But after the presentation, the principal of the school gave him a note.

“Please only share the appropriate parts of the story for our elementary students,” the note read. Nobleman asked for clarification, and was told he should not mention that Fred was gay, or how he died. He also learned that the principal had gone so far as to apologize to parents for the mention of a single gay man.

“We have a responsibility to parents and to guardians that they will know what students are learning in school,” Forsyth County schools spokesperson Jennifer Caracciolo said. Georgia has tried to pass such a law, but it is currently not in effect.

Rather than censor his presentation, Nobleman canceled his further planned appearances immediately.

“We’re long past the point where we should be policing people talking about who they love,” Nobleman said in a telephone interview.