In the past times, the relationships in oriental countries always laid on the shade of parents. Rather than picking his/her lover himself/herself, one must obey the decision of their parents. Sometimes they even did not know their bride or groom at all before the wedding.
Those who wanted to persue their true love needed to revolt by running far, far away with his/her lover, and they would be punished rigiously if caught. As a result, nowadays, to run into a relationship is damned no matter the third party is the boy/girl 's true love or not.
But I know that here is a country of freedom. So I wonder in general, what will happen if a boy comes to like a girl who has already have a boyfriend? Should the boy walk into directly and see the girl's response? Or should he wait until the girl breaks up and then he will have a chance? I know that this situation is bad for all, but sometimes it might be good to throw out what you think?