In an appearance on The Tonight Show Starring Jimmy Fallon, the GLOW star described the couple's first meeting in New Orleans, joking the city was "where all great love stories begin."
The pair were introduced by a mutual friend, who invited Franco to join them for dinner after running into him at the airport. During the evening, their friend texted her under the table and asked if she wanted to "hook up" with the Neighbors star.
"I responded with, 'Yes, please' with a lot of thumbs up emojis. A very enthusiastic response," she said.
Her future husband was equally enthusiastic about the idea, texting back, "I'm in."
The pair's friend told them each about the texts but made them promise to keep the exchange a secret, according to Us Magazine.
"It was the perfect setup," she recalled.
She claimed it gave the two a "sexy secret" as their night of debauchery continued, knowing the other person was "on board."
The 37-year-old said that their initial tryst included "48 hours of drugs and sex a lot of making out."
The stars then met up again in New York, in what Brie called "the wining and dining, romantic portion of meeting each other." On their last day in New York, Franco left a "secret note" on her sweatshirt, asking her to join him in Paris.
"How could I say no?" she said.
The couple dated for three years before getting engaged in August 2015. They married in March 2017.
The Los Angeles native also discussed her new movie The Rental, which is Franco's directorial debut.
The film follows two couples staying in an Airbnb as they discover their host may be spying on them. The vacation soon turns grisly as a mysterious stranger preys on the couples.
In an interview with Insider, Franco said the film was inspired by his own paranoia about home-sharing.
"Every time I stay in a rental home now I'm not thinking are there cameras here but where are they?" he said.
He revealed that he and Brie spent a night on MDMA while preparing for the film, and that they had previously taken the drug when they first met.
A scene in The Rental depicted the characters taking MDMA on their first night, with the exception of Brie's character Michelle. She takes it the next evening, causing her to become oblivious to the gory scenes surrounding her.
The couple used their time in lockdown to collaborate on another project: writing a romantic comedy.
However, Brie told Fallon that the script was not based on their own love story, Us Magazine reported.
"I don't want to cosplay fanfic about our lives but in a negative way," she said.
Brie recently expressed regret for voicing a Vietnamese-American character on Netflix cartoon BoJack Horseman, saying she was "truly sorry," reported The Inquisitr.