I don't know for sure, I just vaguely remember reading somewhere that they had an affair during the first film, but it quickly ended. Than possibly she went to Woody - that I don't know about. Now, to the beginning of GF2 screenings their relationship was terribly bad, and during the filming they made such scandals to each other, that Coppola lost patience and begun to order them both to leave the set at once when they begun screaming at each other again. Then I surmise was a period of time when they didn't want to have much in common.