In Act III, scene v, Capulet is initially confused about why Juliet would refuse the marriage to Paris. Paris is a noble gentleman and a worthy match for Juliet. Capulet soon becomes enraged with Juliet because of her refusal, calling her a “disobedient wretch” and telling her “my fingers itch” (which means he wants to slap her for her behaviour). For Capulet, he feels he has worked hard to secure a suitable match for his daughter and she is not appreciating or respecting his efforts.
Capulet is very quick to anger in this scene. Juliet mentions that she is thankful that her father has made this match for her but that she would like to, at the very least, postpone the wedding. Hearing this Capulet flies into a rage, insisting that Juliet marry Paris or she will be disowned. Juliet, the Nurse, even Lady Capulet, beg him to calm down and let Juliet speak, to explain her feelings, but he will not listen. He does not want to hear Juliet’s reasons for rejecting Paris, and tells her that she must either marry Paris or she will be cast out to “hang, beg, starve, die in the streets.” Capulet only sees Juliet’s refusal and is insistent on ensuring that she heeds his command.
Basically the Capulets were outrage especially Lord Capulet . He didn't understand why Juliet would refuse and thought she was just being ungrateful . He even threatened her that if she does not marry Paris then she would be disown .
Lord Capulet persona turns from being nice to mean, he threatens to kick Juliet out on the streets. His reaction is based on anger and disappointment- By Kat