The Voyeur's Motel by Gay Talese:
He was also not feeling very sociable on this occasion. He had decided to come to the party at the last minute merely as a distraction from his difficulties with Donna. He and Donna had been quarreling for weeks. A day earlier she had gone to an attorney to discuss getting a divorce. Gerald had begged her to reconsider, but she had been angry and unforgiving since learning that he had been having an affair that year with a pretty young woman employed with a public relations agency in Denver.