This is the "Romeo and Juliet" factor. Family feuds, career rivalries, or literal wars provide the pressure cooker that makes the eventual union feel earned and triumphant.

If the answer is yes, the audience will buy the "I love you."

: One character becomes vulnerable and expresses their feelings. The Breakup : A conflict or misunderstanding that forces them apart. Proof of Love

Think of the final shot of Normal People —not a wedding, but two people acknowledging that they changed each other’s biology. Think of the ending of Past Lives —not a embrace, but a walk away. The best romances know that love isn't possession. It is the space you leave for the other person to breathe.