When John returned to Bay City in 1987, there was an immediate physical attraction between them. John tried to convince Donna that there was something between them, but she adamantly denied it. She went to see him at his boathouse and while there, read love letters he had written her over the years but had never sent her. John arrived, and with both their feelings brought to the surface, they undressed and went to bed together. While she gave in to him, John realized he couldn't go through with it -- he simply loved his brother too much. They lay in bed naked and vowed never to see each other again. Unfortunately, Vicky Hudson was watching them through a window, with the end result of Michael finding out and divorcing her.
Years later, in 1992, after Donna had divorced Michael the last time, and John's wife Sharlene Hudson had been dead for several months, Donna and John gave in to their mutual loneliness and slept together one night. That one night of intimacy was all either wanted and so neither pursued a relationship. They remain close friends to this day.