Originally Juliet wasn't opposed to marrying Paris and told her mother that she would meet him at a party to see how she felt about him. At the party, Juliet meets Romeo and the two soon secretly marry. This secret marriage makes Juliet unable to legally marry Paris but at that point, she doesn't want to anyway.
Juliet was just shy of 14 at the time of her marriage to Romeo and he was probably around 15. This young age could be part of the reason for their hasty decision.
Julietmeets Romeo, falls in love, and marries him. After Romeo is banished,Juliet'stears are believed to be in response to the death of her cousin Tybalt. Capulet decides that Julie needsto marryParis.Lady Capulet tells her that she will have nothing more to do with Julie ifshe does not obey her father.