I think its an Idiom. I don't see like or as. So no simile. I don't see he is something like a marshmallow. - No metaphor. I also don't see a non-human thing doing human things- the grass was dancing in the wind. My answer would be an idiom.
Hope this helps!
wait what are we supposed to do?
Answer:
In the opening Prologue of Romeo and Juliet, the Chorus refers to the title characters as “star-crossed lovers,” an allusion to the belief that stars and planets have the power to control events on Earth. This line leads many readers to believe that Romeo and Juliet are inescapably destined to fall in love and equally destined to have that love destroyed. However, though Shakespeare’s play raises the possibility that some impersonal, supernatural force shapes Romeo and Juliet’s lives, by the end of the play it becomes clear that the characters bear more of the responsibility than Fortune does.
Explanation:
This line leads many readers to believe that Romeo and Juliet are inescapably destined to fall in love and equally destined to have that love destroyed. This is the main part of the story.
because, it is easier to use plants or things of that type other than using human trials which can be lethal if done wrong.