All Comments on 'Sandy, Lee and Me: The End'

I enjoyed the buildup to the stories; but to me the last couple of chapters were a letdown and left some unanswered questions. My understanding from the last chapter is that Sandy & Lee had a relationship in college. But was the encounter with Lee planned beforehand by the women? If so why the guilt trip or was it just way to leave? Or perhaps it should have happened when Sandy was present?