Enligt den här webbplatsen Beslut fattades av Alan Burnett, Bruce Timm och Brian Azzarello tillsammans:
The decision for the two superheroes have casual sex, made by Bruce Timm, Alan Burnett, and screenwriter Brian Azzarello, changes several aspects of both the character’s histories, and twists the film’s overall interpretation of Alan Moore’s infamous comic. Although a sexual or romantic relationship between the two had been teased in some ancillary Batman canon projects (specifically in Batman Beyond), their union is not a mainstay in Gotham stories. Still, director Bruce Timm defended the decision to put in a Wayne-Gordon sex scene.
“It was really important to us to show that both of the characters make some pretty big mistakes. I mean, his ‘parental skills’ aren’t that great,” Timm told Vulture. “Maybe never having had any kids of his own, he doesn’t realize that if you tell a kid to not do something, they’re going to want to do it even more. And then she makes some mistakes and then he kind of overreacts to her mistakes and then she overreacts to his overreaction. So it’s very human; it’s a very understandable story.”
I intervjuen på webbplatsen länkar till Timm säger detta specifikt, även om det preliminärt lägger den ursprungliga tanken vid foten av Brian Azzerello:
I'm guessing there will be a lot of conversation after the movie's release about the sex scene. At what point in the creative process did you come up with that idea?
It came from a three-way conversation between [co-producer] Alan Burnett, [screenwriter] Brian Azzarello, and myself. I don't remember who initially came up with the idea, but we all kind of jumped on it all at the same time and said, Yeah, that's kind of where we need to go. My memory kind of says it was Brian, maybe, who came up with the idea. But I'm not sure.
Det bör förstås noteras att Azzarello arbetade inte på de tidigare inkarnationerna av animerade Batman med Bruce Timm och Alan Burnett, som Batman Beyond (där båda co-utvecklade och producerade serien), som inkluderade som backstory som Bruce och Barbara en gång hade ett förhållande, och Batman: Batwoman Mystery (skrivet av Burnett) som också hade några tecken på ett förhållande, eller åtminstone attraktion. Så även om Azzarello kanske har varit den första som säger det vid det bordet, är det också möjligt att han fick tanken från de andra två där och deras tidigare arbete och bara var den som röstade idén att de borde lägga den på skärmen i den här filmen.