From The Telegraph:
Loree Rackstraw has given the first details of the 40-year relationship for the first time since the American writer's death in 2007. In a forthcoming “intimate biography”, the English professor recalls the “great bear of a man” that wrote her letters and took her on romantic holidays. The literary love-story, which continued despite long periods of absence and his two marriages, began when Rackstraw attended a writers' workshop at Iowa University led by Vonnegut in 1965, four years before Slaughterhouse-Five was published.
Rackstraw's book will be published in April, almost exactly two years after Vonnegut died following a fall at his home in Manhattan at the age of 84. She had written often about Vonnegut's work but it was only after his death that she trawled through the collection of letters with the thought of writing something personal. “I realised I possessed quite a remarkable chronological story of his life,” she said. “We were very close. It was a friendship unlike any I've had with anyone.”