First Kill season 1 ending, they don't let that stop them.
Following the plotline of Shakespeare's Romeo and Juliet, First Kill has two warring families, who are constantly at odds with one another. Juliette's family are legacy vampires, a more powerful type of vampire that is born rather than turned. They have a pure bloodline, making them much harder to kill. Cal's family are monster hunters working with an organization called the Guild. Their job is to get rid of all supernatural creatures, which includes Juliette and her family. Cal and Juliette meet and fall in love, but their families have other plans.
However, by drawing such close parallels with Romeo and Juliet, First Kill may have doomed the characters to a tragic ending from the very moment they met. In fact, Cal is already planning to drive a stake through Juliette's heart, believing her to be a monster. Their makeout session in the closet is interrupted when Juliette's bloodlust takes over and she bites Cal. In return, Cal stakes her, but Juliette lives and the two find themselves linked. Cal's heart does begin to soften and the two pursue a relationship, which their families try and fail to prevent. Romeo and Juliet also date in secret and defy their parents, believing nothing can come between their love. However, the famous ending of the book ends in anything but happiness, and already, First Kill is setting up Juliette and Calliope's relationship to end in a similar way.
The parallels between First Kill and Romeo and Juliet aren't limited to them being star-crossed lovers. In the Shakespeare play, when Romeo accidentally kills Juliet's cousin, Tybalt, it seems their love may be impossible. First Kill's Juliette and Cal have a similar problem. Juliette accidentally turns Cal's brother Theo (Phillip Mullings Jr.) into a vampire, a form of betrayal Calliope cannot easily forgive. Unable to see past her anger, Cal breaks up with Juliette. From the moment their relationship begins, they betray one another, so the foundation of trust is already broken.
The end of Romeo and Juliet sees the two united in death, so Cal and Juliette could find themselves in the same situation. Calliope makes it clear to Juliette that, while her family of monster hunters don't know how to kill legacy vampires now, she will spend the rest of her life trying to figure it out. If Netflix announces a First Kill season 2, there's a chance that Cal will figure out how to kill legacy vampires and she may reveal this information to The Guild. This would prove to be a mistake she can't take back. If the parallels with Romeo and Juliet continue, Cal and Juliette may find themselves at odds with their families, The Guild, and the rest of the legacy vampires. Even if they are reunited, it's entirely possible their romance in First Kill won't have a happy ending.