If one spouse forgives the other for cheating, why does it (always) get brought up in conversations long after the cheating has ended and after the forgiveness has been granted? (Question asked “online”)

Here are four, of many, reasons:
1. Sexual infidelity severely wounds people (all people involved) and relationships on many levels. Its power to shake life ought never be underestimated. Betrayal cuts a deep wound and often dislodges the capacity for future trust. (This is for the victims and the perpetrators!)
2. Because of the intense intimacy that can accompany the sex act, the betrayed spouse might go on a quest to know if the “stolen sex” led his or her partner into deeper levels of intimacy than were achieved within the marriage.
3. The forgiver will probably interpret silence (or anger, or even “over” focus) as an indication the affair did not really cease, or that it has been re-ignited.
4. Talking can connect people, and it can (but does not always) offer hurt people a sense of legitimate control and order. People who have been betrayed often want to talk about their experience (hurt, pain) as an attempt to stop their lives from (the feeling of) running totally out of control.

Men and women who have participated in infidelity, and who yet have a forgiving spouse who is willing to work on the marriage, are encouraged to talk openly about anything the forgiving spouse may want talk about. There are some necessary limits to this which I will go into in another posting.