Why does Calpurnia stop Caesar from going to the Senate and how does he react?
Calpurnia has a horrible nightmare the night before Caesar is murdered. She dreams that Caesar's statue is as a fountain with blood flowing from it. For this reason, Calpurnia begs Caesar to stay home and not go to the Capitol:
Calphurnia is Caesar's wife. In II.ii, she is concerned about the bad omens, which she frankly admits she has never put much credence in before this time. When Calphurnia gets on her knee to Caesar, she temporarily succeeds in persuading him to remain at home. She offers to let Caesar use her anxiety as an excuse for not going to the Capitol.
At first, Caesar gives in to Calpurnia. He agrees to stay home to please her. Then Decius, one of the conspirators, ridicules Caesar for giving in to his wife's fears. He makes Caesar feel foolish for giving in to his wife's pleas.
Then Caesar speaks to Calpurnia as if she has been foolish for having nonsensical fears. Caesar gently criticizes Calpurnia for causing him to give in to her fears:
How foolish your fears seem now, Calpurnia!
I’m ashamed that I gave in to them.
Give me my robe, because I’ll go.
He decides to go to the Capitol after all.
Caesar should have given in to Calpurnia's real fears. She was trying to save his life. Caesar disregarded her pleas to stay at home. He was stabbed thirty-three times at the Senate-house.