In The Scarlet Letter, Hester feels tremendous guilt for having kept the identity of Roger Chillingworth secret. For, she feels that she has been the "bane and ruin" of the man she loves. In Chapter XVII, Hawthorne narrates,
Hester felt that the sacrifice of the clergyman's good name, and death itself, as she had already told Roger Chillingworth, would have been infinitely preferable to the alternative which she had taken upon herself to choose.
She would almost "rather lie in the half-strewn leaves and die" than confess the identity of Chillingworth, but Hester bravely tells the Reverend Dimmesdale, who responds, "I cannot forgive thee!" However, he does forgive her, but he decries the physician who has "violated the sanctity of the human heart."
In Chapter 15, it states that the worst crime she feels she had committed is simply having accepted the advances of Roger Chillingsworth and having ever reciprocated him. She feels that because of this, she was an agent of transformation and made him also a bad person. It was her sin what made him bad, she thought. She was fully aware of the consequences that her cheating caused, but she was also willing to accept that these decisions affected more than one person. She felt horrible about it, but mostly horrified that she had even loved Chillingworth once, a man whom she never really cared for in the first place.