Early in The Crucible John Proctor is contrite with his wife Elizabeth and seeks her forgiveness for the affair he had with Abigail Williams.
At the beginning of the play, Proctor attempts to convince Abigail that their affair is completely over and that she should expect nothing more from him. During this conversation, Abigail tells Proctor why Betty is in bed, suggesting that Betty is not really sick at all.
She tells him that it is all pretense and that Betty is just scared.
This knowledge becomes important when accusations of witchcraft begin to be made against townspeople. Proctor tells Elizabeth what Abigail had told him and Elizabeth insists that Proctor share his knowledge with the authorities before things could get out of hand.
Proctor believes that the truth will soon enough come out on its own, but Elizabeth insists that he go to Salem. When he refuses Elizabeth believes that he is trying to protect Abigail. Her suspicions are an outgrowth of her jealousy and pain at having been cheated on by John Proctor. She is not confident that the affair is completely over, despite Proctor's repeated claims that it is now ended.