Images of (and references to) stars recur repeatedly throughout the play, standing in for both cruel twists of fate and notions of romance. In the Chorus's Prologue, for example, Romeo and Juliet are described as "star-crossed lovers" who will later die by suicide, suggesting that their love for one another is predestined, just like their untimely deaths: neither fate can exist without the other.
Romeo in particular is aware of the stars portending his fate. When he forecasts his own death in Act 1, he refers to the stars, which he sees as guiding his own destiny: "Some consequence yet hanging in the stars / Shall bitterly begin his fearful date / With this night’s revels." Later, when he receives the news of Juliet's apparent death in Act 5, he cries out, "Then I defy you, stars!"—clearly connecting the stars to Juliet's death, which he understands as both inevitable and wholly devastating. Finally, before killing himself in Act 5, Romeo rues the stars for his bad fortune, comparing them to a "yoke" that binds him: "O, here / Will I set up my everlasting rest / And shake the yoke of inauspicious stars / From this world-wearied flesh!"
When Juliet comments on the stars, though, it is to liken Romeo to them, as in her soliloquy in Act 3, Scene 2:
Give me my Romeo, and when I shall die,
Take him and cut him out in little stars,
And he will make the face of heaven so fine
That all the world will be in love with night
And pay no worship to the garish sun.
Here, Juliet is obliquely referencing the sex she and Romeo are about to have—"die" is an Elizabethan euphemism for having an orgasm—and using the image of stars to underscore the transcendent, heavenly passion she expects to experience during their sexual tryst. This image also makes it clear that Juliet is talking about sex: Romeo's face will literally appear above hers during the act of sex, just as stars appear above the Earth.
Yet, by simultaneously referencing death and suggesting its inevitability (saying "when I shall die," instead of "when I may die"), Juliet's interpretation of "stars" aligns with the interpretation that Romeo continually uses. Unbeknownst to her, Romeo feels plagued by the stars, which he believes have prophesied his own bad luck and tragic destiny—the latter of which is now intertwined with Juliet's. This parallel suggests that the lovers are deeply connected on several different levels: not only through their fierce love for one another, but also through language and their intrinsic understanding of fate.