When is an American story not an American book? When the subject may run afoul of Son of Sam laws, which still bedevil publishers and authors of books involving people in jail. The story of Mary Letourneau, the married Seattle schoolteacher who had a child with one of her pupils, young Samoan Vili Fualaau, and was sent to jail for it, has been covered in news stories here, but it was a Parisian publisher, Bernard Fixot of Laffont, who bought her story for a book called Forbidden Love (in French, Un seul crime, l'amour) co-authored by the lovers. He has world rights, will be selling English-language at Frankfurt, and has already sold Italy's Mondadori on the story.