Romeo is really not inclined to accompany Benvolio, but he agrees to enter into the Capulets' celebration so that he can again see Rosaline, who will be there.
After the illiterate servant of the Capulets mistakenly asks Romeo to read the invitation that he has been sent to extend to friends of this family, Benvolio makes the argument with the love-sick Romeo to go with him to this celebration because there he can compare Rosaline, who has ended their relationship, with the other maidens and realize that she is not so beautiful as Romeo believes.
At this same ancient feast of Capulet’s
Sups the fair Rosaline whom thou so loves
With all the admired beauties of Verona....
Compare her face with some that I shall show,
And I will make thee think thy swan a crow. (1.2.84-89)
Romeo reluctantly agrees to accompany Benvolio, but only because he will have the opportunity to see Rosaline again.
This exchange of Benvolio and Romeo exemplifies dramatic irony
since Benvolio's prediction that Romeo will think Rosaline "a crow" and forget about her actually occurs as Romeo is immediately smitten when he sees Juliet
. The audience, of course, recognizes this dramatic irony since they have been told in the Prologue
of Romeo and Juliet
's love, the "star-crossed lovers" from the "fatal loins of ...two foes."