Romeo is presented as a unstable young boy who just lost a bet. Benvolio asked him to go to the Capulet party so he could prove that Rosaline isn't the only pretty face in town. Romeo isn't there two minutes and he's declaring that he's in love! Benvolio said he would prove that Romeo's "swan" would seem like a crow and Romeo replies at the party, "So shows a snowy dove trooping with crows,/As yonder lady o'er her fellows shows" (I.v.48-49). It is as if he is completely bipolar because in the previous scene he is still moping around over Rosaline and then completely flip-flops when he sees Juliet. That doesn't present the audience with a stable view of the boy. He is controlled by the emotions he feels at the moment.
he is presented as a scouser
Romeo, seeking Rosaline through the crowd, sees Juliet instead. He is awe-struck by her grace and beauty, and he completely forgets Rosaline. Romeo's heart is racing as he exclaims, "O, she doth teach the torches to burn bright!/It seems she hangs upon the cheek of night/As a rich jewel in an Ethiop's ear" (1.5.46-9).