Ethan Ogilby doesn’t know where the idea came from, but he knew he could write a script about it.

“It just popped into my head one day, and I wondered what would happen if there was a threesome and two of the people got pregnant,” said Ogilby, 40, a Maine native who’s worked in film and TV for more than a decade, including on “The Simpsons.” “It just stuck in my head and I thought it might make a pretty good movie. It would be funny and ridiculous, but also very serious because the stakes would be pretty high for all involved.”

Ogilby turned the idea into the script for a romantic comedy film called “The Threesome,” which was released in theaters in September and will be streaming October 3. The indie film, the first feature for Ogilby as a screenwriter, stars Jonah Hauer-King, Zoey Deutch and Ruby Cruz.

Director Chad Hartigan said reading Ogilby’s script reminded him of classic romcoms of the 1980s and 90s, like “Working Girl,” “Jerry Maguire,” or “Broadcast News,” that could combine a romantic story with messy characters and complicated dynamics.

“Back in the 1980s and ’90s, iconic directors were finding ways to play in the genre in more grounded and elevated ways,” Hartigan said, in a statement in the film’s press kit. “When I first read Ethan Ogilby’s script, I saw my opportunity to attempt that type of romcom.”

The film’s story focuses on a young man named Connor, played by Hauer-King, and the young woman he’s had a crush on for a long time, Olivia, played by Deutch. They had met while working at the same restaurant. One night Conner starts a conversation with Cruz’s character, Jenny, in an attempt to make Olivia jealous. But Olivia joins the flirting and the evening evolves into the title threesome.

Once it’s revealed that both women got pregnant at the same time, the story gets serious, while still filled with humor. There are jokes about how Connor must have the most potent sperm in the world, but heartfelt moments where the trio tries to navigate the serious issues of parenthood and commitment. The trio goes to doctor visits, to meet family, to birthing classes and to try to plan out their separate and entangled futures.

Hauer-King starred as Prince Eric in Disney’s live-action “The Little Mermaid” in 2023, while Deutch, the daughter of actress Lea Thompson (“Back to the Future”) starred in a revival of “Our Town” on Broadway and was in Clint Eastwood’s “Juror No. 2” in 2024. Cruz was recently in the HBO Max series “The Sex Lives of College Girls.”

Once he came up with the idea, Ogilby said he did some research to see if he could find instances of such a rare occurrence ever happening in real life, but could not. Still he liked the idea of a complicated plot with less of a fairytale feel than many romcoms.

“I like indie romcoms, where they take it seriously and embrace how complicated things can get. I think a lot of studio romcoms are sanitized and saccharine,” said Ogilby. “I think this movie gets at the tension that would be involved in a situation like this. “

Ogilby, who is based in Los Angeles, wrote the story to take place in New Orleans, because he thought it would be a place where “cool young people might live.” Plus he hoped the movie would be filmed wherever it was set, and he’d heard that Louisiana was generous with financial incentives for film production. But the film’s producers found more lucrative tax breaks in Little Rock, Arkansas, so the story was set and filmed there.

“I think it gives the movie an interesting texture. It’s not a place where you see a lot of movies shot,” said Ogilby. “It seems like a ton of things were being shot in Atlanta for a while, so I think the location gives it sort of a unique quality.”

Ogilby grew up in Bowdoinham and was interested in books, writing and films early on. In his fifth grade yearbook he wrote he wanted to be a film director and live in Portland, the big city to a youngster from Bowdoinham. He thought about making the “Lord of the Rings” books into movies someday, but somebody else beat him to it. He went to Mt. Ararat High School, graduating in 2004, and enrolled at Johns Hopkins University in Maryland to study writing. But it took a few years before he started to think seriously about writing for TV or films.

“It never truly occurred to me until I was about 20 years old that writing those things that I liked and consumed, TV and in film, could be a job,” said Ogilby. “

After graduating from college he stayed in Baltimore for a year or so and eventually got a job as an assistant to a writer named Billy Kimball, who went to school with his mother and had written for late night TV shows as well as the sitcoms “The Simpsons” and “Veep.”

He moved to Los Angeles, rooming with other would-be writers, and looked for work. He landed a job in production on “The Simpsons” from about 2013 to 2016. He left for a while and then came back an assistant editor, around 2021. The bulk of his job is making sure recorded audio, voices and music, are ready for the animators, who use it in their creative process, but not necessarily in the finished version of the show. He’s still with the show.

In between stints for “The Simpsons,” he worked with as an associate producer on a series of Netflix music-themed documentaries called “ReMastered.” One was on the violent death of 50’s pop singer Sam Cooke, another was about Johnny Cash’s White House concert during Richard Nixon’s presidency and another was about the long battle over royalties connected to the song “The Lion Sleeps Tonight.” He did a lot of archival research for the films.

But working as an editor and a researcher didn’t fulfill Ogilby’s desire to write and create his own stories. So he worked on scripts while working his day jobs, including several for TV series episodes on “spec,” meaning he wrote them without knowing if anyone would want them. At one point he and his wife, Megan Mock, a labor and delivery nurse, wrote a pilot for a TV sitcom focusing on labor and delivery nurses.

The sitcom pilot got them representation at one of Hollywood’s largest talent agencies, which eventually led to Ogilby finding people who wanted to produce “The Threesome.” His wife ended up playing a nurse in the film.

He’s currently working with his wife on another romcom, though he says it will have “a little more of a mainstream premise” than “The Threesome.”

“I feel like I’ve been a semi-professional writer for the last ten years, having a bunch of projects that don’t quite get across the finish line,” said Ogilby. “It would be great if I could piggyback onto whatever modest success ‘The Threesome’ might have.”