In act 1, as Mercutio, Romeo, and Benvolio head to the Capulet party, Romeo moons for Rosaline, his unrequited love. Mercutio wants him to snap out of this lovesickness, so he pictures love as a rival that Romeo must beat down, saying,
If love be rough with you, be rough with love.
Prick love for pricking and you beat love down.
Love becomes the enemy who must be defeated.
Tybalt, who is always ready for a fight with a Montague, is angered to see one of his rivals, Romeo, flirting with his cousin Juliet. Spoiling for a fight, Tybalt says,
Uncle, this is a Montague, our foe ...
Lord Capulet, however, does not want a quarrel to break out at his party and tells Tybalt to leave Romeo alone.
In act 3, Tybalt is still looking for a chance to fight Romeo, whom he continues to consider a particular rival since Romeo danced with Juliet at the party. Tybalt insults Romeo on the streets of Verona, hoping to provoke a sword fight. He says to Romeo:
Romeo, the hate I bear thee can afford
No better term than this,—thou art a villain.
Romeo, newly wed to Juliet, wants no quarrel with his new cousin and tries to greet Tybalt with kind words. This causes Tybalt, in the same scene, to state,
Boy, this shall not excuse the injuries
That thou hast done me; therefore turn and draw.
When Paris, at Juliet's grave in act 5, sees Romeo, he reacts to him as a rival Montague, the man whose killing of Tybalt caused Juliet's death. Paris says to him:
Stop thy unhallow'd toil, vile Montague!
Can vengeance be pursued further than death?
Condemned villain, I do apprehend thee:
Obey, and go with me; for thou must die.