Why does Benvolio want to bring Romeo to the Capulet party? What is the only reason Romeo will go?

Benvolio sees that Rosaline will be at the party and he wants Romeo to do a comparison of her beauty next to other beautiful girls at the party. Romeo can't imagine a girl prettier than Rosaline, but begrudgingly agrees to go to the party so that he can stare at Rosaline.