The Scarlet Letter what is Hester prynne's crime?

She had an affair with Dimmesdale, the minister, while she was still married to a man, Roger Chillingworth, who had been in the woods for a long time. She did not love Chillingworth (thats not his real name by the way, but the narrator does not remember it and that is what Chillingworth addresses himself as.) she was in love with Dimmesdale. She got pregnant and little Pearl came out. The Magistrates questioned who was pearls father but she never told. it was not really a crime, it was more of a sin i guess.