What are Romeo's and Juliet's reactions when they discover they have fallen in love with their family's enemy?This is a high tension point. What will happen to them?
Both Romeo and Juliet learn the horrible news about each other's familial relationship sin Act 1, Scene 5. The nurse must be the bearer of bad news to each of them. She first warns Romeo by telling him he has set his sights on the daughter of the lady of the house. Romeo is flabbergasted. "Is she a Capulet?" he cries. "O dear account. My life is my foe's debt." Benvolio tries to dissuade his love-struck friend. "Away, be gone, the sport is at the best," he advises (1.5.115-20).
Juliet's nurse is then has the unpleasant task of telling her charge:
Nurse: His name is Romeo, and a Montague, / The only son of your great enemy.
Juliet: My only love sprung from my only hate. / To early seen unknown, and unknown too late. / Prodigious birth of love it is to me / That I must love a loathed enemy.
This is a high tension point because it is at this juncture that both of the young lovers must decide to break off on their own, to "deny their families, (and) to refuse (their) names." Doing so could lead to dire consequences. As children of the elite, they are dependant on the fortunes of their families, dowries, and connections to get along in the world. They have no trades of which to speak and nowhere to go. It is likely, given the history of the feuding families, that both would be disowned.