Can you write a fictional book about real celebrities?

Roman à Clef
Roman à clef (pronounced roh-máhn a clay) is French for "novel with a key." It's a novel in which actual events are given a superficial fictional mask; but, with the "key," can be read as a more or less faithful account of true events. They're often used to report scandals while avoiding charges of libel or sedition.
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From the Guide to Literary Terms by Jack Lynch.

Satire as free speech

But major media groups including the Association of American Publishers, the Motion Picture Association of America, and the Cartoon Network have filed a brief supporting the newspaper's case.

"An adverse decision at the Texas Supreme Court would have a chilling effect on the use of satire in the media," says James Hemphill, lead attorney for the Observer. "Even the specter of having to go to trial and incur the expense of defending political speech is enough to chill that speech."

When the Observer first ran its piece, Isaacks and Whitten were deluged by angry letters and even calls for their resignation. The two officials sued the paper for libel.

Both the trial court and the Texas Court of Appeals agreed with Isaacks' and Whitten's view that satire is in the eye of the beholder. "Satire is not protected under the First Amendment if it fails to make clear to its readers that it is not conveying actual facts," the appeals court wrote.

Avoiding libel in satire

Satire, caricature and parody are forms of art that rely on blurring the line between truth and outrageousness. Below are suggestions ?- some taken from opinions in New Times v. Isaacks, decided in September by the Texas Supreme Court, and the 1988 U.S. Supreme Court decision in Hustler Magazine v. Falwell ?- of things to include to help make it unlikely that a reasonable person would believe the story to be actually true. The context of the entire story is important, so no single suggestion is guaranteed to protect from liability. It is also not necessary to include all of the suggestions below.

• Use of an irreverent tone will signal that the story is not straight news.

• Consider the context of the publication the story will run in, including whether the publication has a history of satire or parody. The Wall Street Journal should be more careful than Mad Magazine.

• Consider the location in the publication. Is it in the news section, the opinion page or an advertisement?

• Use of an unorthodox headline will alert readers from the beginning that the story is not straight news.

• Unbelievable or outrageous items in the story, experts or groups with names that are ridiculous or have a silly acronym, and quotes that are unbelievable, illogical or over-the-top may all signal that a story is not stating actual facts.

• Instead of using the names of actual people, consider using fictitious names that are close to or suggest real people.

• In the story, consider referring to the actual incident you are parodying. Publishing the parody soon after the actual incident while it is still in the public's mind provides a clue that the story is commenting on the actual event.

• Use of a disclaimer may help, but will not necessarily avoid liability, especially if in small print at the end of an otherwise believable story.

?- GP

Like say I wanted to write a book about A wild gay love triangle between George Bush, Dick Cheney, and "Miss Beazley" the Bush's pet Scottish terrier. Could I do that? What could happen to me if I did that?