The answer to this question is really up to the opinion of the person who is answering it because it can go either way depending upon the morals and values of the interpreter. One could say that Romeo lies to everyone close to him and becomes extremely disrespectful to his family, especially his parents. He does not care about anyone except for himself since he rushed into a marriage with a girl that he barely knows just because she is beautiful and then murders her cousin out of anger and self-pride.
However, you can also argue that Romeo is a confused teenager who does not understand the way that the world works. He finally finds a beautiful girl who understands him and loves him back. In order to make sure that he never loses her, he impetuously rushes into a marriage without telling his parents because he fears that they will keep him from her and then murders his wife's cousin in an effort to avenge his poor friend who was just murdered.
The interpretation really depends upon how you look at the character -- is he a careless young man who will stop at nothing until he gets who/what he wants or is he a confused teenager who finally found someone who understands him?