At the beginning of the play, Juliet illustrates the expected level of obedience to her parents in who she should marry when she responds her mother's question of whether she could love Paris in Act I, Scene 3: "I'll look to like, if looking liking move: But no more deep will I endart mine eye/ Than your consent gives strength to make it fly". Juliet would only allow her feeling to go as far as her parents would allow and consent to.
Her parent's reaction to the Juliet's declaration that she will not marry Paris on Thursday in Act III, Scene 5 shows the reactions and consequences of Juliet's disobedience to her parent's wishes.
Lord Capulet: "Hang thee, young baggage! disobedient wretch!/ I tell thee what,--get thee to church o' Thursday, /Or never after look me in the face:/ Speak not, reply not, do not answer me;/ My fingers itch.--Wife, we scarce thought us bles'd/ That God had lent us but this only child;/ But now I see this one is one too much,/ And that we have a curse in having her: Out on her, hilding!"
Lady Capulet: "Talk not to me, for I'll not speak a word;/ Do as thou wilt, for I have done with thee".
Both Lord and Lady Capulet are willing to disown Juliet helps to illustrate why Juliet would be unwilling to tell her parents that she had not only married against their wishes, but to the son of her family's mortal enemy.