How is Romeo a mature partner in his relationship?
Romeo acts like a mature partner to Juliet when he tries to hold off Tybalt when Tybalt comes to fight him. Although he has always despised Tybalt, Romeo is now married to Juliet, Tybalt's cousin, and so he does his best to resist Tybalt's insults and remain calm. Tybalt is upset that Romeo and his friends showed up at the big Capulet party. In response, Romeo says, "I do protest I never injured thee, / But love thee better than thou canst devise, / Till thou shalt know the reason of my love. / And so, good Capulet—which name I tender / As dearly as my own—be satisfied." In other words, Romeo says that he loves Tybalt, though Tybalt cannot now understand why; he claims that he loves the Capulet name as much as he loves his own. Romeo and Juliet's marriage is a secret, and so he cannot tell Tybalt why he wants to avoid a fight with him. However, he does show his maturity and tries to prevent a fight from starting. Even when Mercutio steps up to fight Tybalt in Romeo's stead, Romeo still tries to intervene, protect his friend, and prevent harm from coming to his wife's cousin. In fact, it is his intervention that actually allows Tybalt to slay Mercutio when Romeo comes between them.