ROCK HUDSON The Real Story of Rock Hudson's Marriage to Phyllis GatesBy Phyllis Gates and Bob Thomas Doubleday. 232 pp. $16.95

Poor Rock Hudson. First he dies of AIDS, then his ex-wife -- with the help of Bob Thomas, "author of a number of celebrity biographies" -- writes a book about him. Phyllis Gates was married to Hudson for two years; apparently she stayed sore about it for the next 30.

We learn too much about Phyllis -- her Minnesota childhood, her first job, her first stay at the Beverly Hills Hotel ("I realized that this was where I wanted to spend the rest of my life") -- and almost nothing about Rock. Because, by her own admission, Phyllis never knew much about Rock. She says he had black moods and didn't like to share his secret thoughts.

She does describe his grin at great length. Sometimes it's "irresistible," sometimes it's a "million-dollar grin," sometimes it's a "quizzical, little-boy grin," but this book is so depressing, it's hard to imagine what he was grinning about.

This book is mean-spirited too, and once the authors get going, fairly lurid. Do you really want to know that Rock said "all women are dirty"? Or that he leaped around, "completely nude," pretending to be a ballet dancer? Or that he didn't like to brush his teeth?

Let me tell you, Phyllis had big problems, and not just the brevity of Rock's lovemaking, either. He slept with his arm across her body, and his arm was too heavy. He once suggested, "Why don't we have someone join us in bed?" Strange young men used to telephone and ask to speak to him. Director Richard Brooks was foul-mouthed, yet Rock made no move "to suggest that such language was not polite in front of his wife." Rock used to soak his blue jeans and then put them on wet so they'd cling to his body. And Rock's agent, Henry Willson, behaved for all the world like a jealous mother-in-law.

Phyllis remembers the menus of every meal the Hudsons ever ate, but she remembers nothing that matters.

Phyllis is a snob. When they're on their honeymoon and Rock okays the room the hotel has assigned them, Phyllis rebels: "I was aghast. It looked like an oversized closet. 'Rock, we can't stay here,' I said."

Phyllis is unwittingly funny. She tells the story of a drunken Humphrey Bogart taunting Spencer Tracy. " 'You know, Spence, you never really made it,' Bogie muttered. 'There was always Gable.' Tracy smiled sourly."

Two paragraphs later, she says of Bogart, "He was such a kind, thoughtful man." Tell it to Spencer Tracy.

Phyllis is wiser than Rock's agent. She advises Rock to play Ben-Hur, but Henry Willson says no. "And of course," Phyllis recalls, "Charlton Heston won the Oscar for it."

Phyllis is competitive with her husband. According to her, every second person she met wanted to make her a star. Agent Henry Willson: "I shouldn't hire you as a secretary. I should get you a studio contract." A casting director at Fox: "You're the one I should be interviewing. How would you like to take a screen test?" Rock himself: "You know, if you ever decided to become an actress, Phyllis, I'd have to move over. You'd be a big hit."

And when Phyllis and Elizabeth Taylor accompanied Montgomery Clift to the hospital after his near-fatal automobile accident, Phyllis says Rock stopped talking to her for several days. "Was it," she asks, "because I had been in the spotlight and he hadn't?"

How's that for a nasty speculation?

How's this for a nasty book, when you come right down to it? Despite the phone calls from young men, Phyllis insists she didn't know about Hudson's homosexuality until her divorce lawyer, Jerry Giesler, suggested to her that the marriage might have been a "cover-up for Rock's true nature."

You can't imagine what a shock this was to Phyllis. In a town where gossip is the second largest industry, she had never heard a peep. Nor had she guessed anything. Either Phyllis Gates was the dumbest woman who ever lived, or Rock Hudson was the greatest actor.

Almost the worst part of this self-serving testament is that Phyllis regularly interrupts the recital of her woes to avow her passion for the husband she is trashing. "I realized how deeply I loved him." " 'I still love my husband, Mr. Giesler,' I said, 'but I can only conclude that he no longer loves me.' "

You may not love her either. Chris Chase is coauthor, with Betty Ford, of "Betty: A Glad Awakening."