Probably because he is mad at Romoe for crashing his uncles party and since Capulet doesn't want him to be around when he's angry he leaves.
Romeo tells off Tybalt at the ball in "Romeo and Juliet." He does so in a polite manner, trying to diffuse the tension between Tybalt and himself.
by his voice
Romeo is wearing a mask. It is a masked ball.
Benvolio
Tybalt recognizes Romeo at the ball in the beginnign of the play by his voice. To be precise, he recognizes him as a Montegue for this reason.
Capulet's Ball is open to everyone except the Montagues (the family which has a traditional enmity with the Capulets). When Tybalt (a Capulet) realises that Romeo (a Montague) is at the Ball, he wants to start a fight. But Old Capulet (Juliet's father) tells Tybalt that it is a party, and that Romeo seems a nice enough fellow. Tybalt is very angry that he has been prevented from starting a fight. But it isn't so difficult to work out who Romeo is. At the end of the party, when the guests are starting to leave, Juliet asks her nurse to find out who the young man was that Juliet has been talking to. It takes the nurse a few moments to ascertain that it is Romeo - but only a few moments.
tybolt
Tybalt is looking for Romeo because he wants to challenge him to a duel due to his anger towards Romeo for attending the Capulet ball uninvited.
Tybalt recognizes Romeo's voice and immediately prepares to duel him, since duelling is all that Tybalt is interested in.
Tybalt is not planning to forget that Romeo intruded into the Capulet's ball, and he will get REVENGE! Lol He is disgusted by him. PS- Betty Rollin's Legs :D
Tybalt is a fictional character in the play, Romeo and Juliet. He left the part in anger because he noticed that Romeo was at the party.
he sends him a message challenging him to a deul, as romeo humiliated him by turing up to Tybalt's families masquerade ball, so Tybalt feels as if he needs to seek revenge onm Romeo.