Based on the novel of the same name by Shannon Pufahl. The character of Muriel (played in the film by Daisy Edgar-Jones) was inspired by Pufahl's grandmother and her experiences in the world of gambling in the 1950s.
The first promotional still of the film created the misleading impression that the story might include a romance between Muriel (Daisy Edgar-Jones) and Julius (Jacob Elordi). In fact, there is no love affair between Julius and Muriel in the film: Julius is actually gay and in love with a man.
At the beginning of the film, Julius tells Lee and Muriel he was discharged from the Navy six months early and did not receive mustering out pay. No further explanation is given, but it seems he received either a dishonorable discharge for committing a crime such as theft, or an "undesirable" discharge because he was gay; later in the film, Julius says during his Navy service he was both a thief and a (slur for homosexual). Mustering out pay was guaranteed by the U.S. Congress in the G.I. Bill to any war veteran who was discharged "under conditions other than dishonorable." Undesirable discharges were officially termed "neither honorable nor dishonorable" but the Veterans' Administration denied all benefits to those discharged as homosexuals, on the premise that they had been discharged "under dishonorable conditions." The discharges were given to anyone who was determined by psychiatric examination to be homosexual or to have "homosexual tendencies," whether or not the person was known to have committed any homosexual act.
The film has received criticism on social media for marketing and publicizing the film in a way which has frequently downplayed, and in some cases entirely erased, the queer love stories between Julius/Henry and Muriel/Sandra in the film. While Julius does have a connection with Muriel, it is platonic, and the majority of his character's story is actually focused on his relationship with Henry, the man he loves.
Despite the emphasis of the marketing on the connection between Daisy Edgar-Jones and Jacob Elordi's characters, the director Daniel Minahan acknowledged in an interview that they share no more than 15 minutes of screen time in the film with each other, a small amount given that the film in total is 117 minutes long. While Edgar-Jones and Elordi play the leads, their respective stories take place mostly separately, and Elordi actually has more scenes with the actor who plays his male lover, Diego Calva, than he does with Edgar-Jones.