When the Friar tells Romeo of the Prince's decree following his discovery of the death of Mercutio and Tybalt, Romeo responds to the news that the Prince has visited a "gentler punishment" on him in the form of banishment with despair and grief. Romeo initially responds to this news by ironically mocking what the Friar sees as good news:
Ha, banishment? Be merciful, say "death";
For exile hath more terror in his look,
Much more than death. Do not say "banishment."
Romeo seems to say this in a disbelieving tone, because he believes that death would have been more preferable. When the Friar insists that this is so, Romeo says to the Friar that he is pretending to give him good news whilst in reality giving him terrible news, using the following analogy:
Thou cut'st my head off with a golden ax
And smilest upon the stroke that murders me.
He insists that such a sentence is "torture, not mercy" because for him heaven is where Juliet is. If he can't be with her, and is unable to die to see her from his vantage point in the world beyond, then he is condemned to hell. We can imagine that these speeches would be accompanied by despairing movements and body language, and an angry, hopeless tone of voice as he laments his fate.