SWEETie's diamonds
Diane Boston lives with her Marfan syndrome-afflicted 13-year-old son in a suburb of Chicago and teaches social studies at the high school, with the students even voting her Teacher of the Year. But she has some dark secrets. Her ex-husband Greg always suspected that Diane kept things from him, but he has no idea just how right he is. When Diane's son, David, finds a box of unmarked videotapes and watches one of them out of curiosity, he discovers that it's a hardcore adult movie from the late 1970s. The star, Lucy Luv, was an actress that mysteriously disappeared in 1980. Some suspected she'd been murdered. David recognizes the actress as his mother. Then, somehow, the news of Diane's involvement in the adult film business hits the streets and causes chaos at her school and at home. It also attracts the attention of the West Coast porn czar who has ties with organized crime. Apparently when Lucy Luv disappeared, she took a cache of stolen diamonds with her. This is the catalyst for a non-stop roller-coaster ride of suspense and mystery that involves the dark side of the adult film industry, the mob, kidnapping, and murder.

Hardcover edition from Five Star is still available, too.
Read A Review:

Raymond Benson...has produced an original thriller whose results are as exciting as any of 007's adventures.  SWEETIE'S DIAMONDS tells the story of a suburban Chicago schoolteacher and her teenage son whose quiet  lives are roiled just under the surface by a strong current of dark secrets. Mom may or may not have been a porn star in her younger days, and when a tabloid magazine gets hold of the story, all hell breaks loose. What's certain is that she stole a few million in diamonds from the mob and the wiseguys want them back. Benson turns the screws on mother and son unmercifully, giving the story lots of tension and suspense. SWEETIE'S DIAMONDS is a gem.
David J. Montgomery, CHICAGO SUN-TIMES

When a teenage boy discovers that his mother once starred in pornographic films, he is, predictably, shocked. This is a side of his mom he'd never suspected, but the truth is far more complicated than even your David can possibly imagine. Benson, best known for his popular James Bond novels, proves here that he is equally adept at more realistic thrillers. This ever-more-intricate story (which involves a two-decade-old murder and several buried secrets) may remind some readers of the novels of James Grippando, who tends to structure his high-octane thrillers on families with closets full of secrets. The relationship between David and his mother, Diane (aka Lucy Luv), is key to the drama, and Benson layers enough twists and turns to keep mother and son, not to mention the reader, searching desperately for the truth.
David Pitt, BOOKLIST

On the surface, Diane Boston appears to be maintaining a placid life despite difficult circumstances. She is successfully weathering a recent divorce, while caught up with her teaching duties and the raising of her teen-age son, who is afflicted with Marfan’s syndrome. Beneath the surface, however, something is radically wrong, and that something suddenly breaks to the surface. Old porno tapes begin circulating that show Diane as one of their prime performers. At first, she simply denies that it is her, only later insisting that the actor is, in fact, a long-dead twin sister. As her world begins to crumble around her, the producer of the movies discovers her existence and sends out a hit man to find her and to recover diamonds which were stolen from him and which he suspects she has in her possession. SWEETIE’S DIAMONDS contains about everything that a suspense novel could or should contain. Bodies, past and present, are strewn over the landscape; hair's-breath escapes are the rule; and a first-class car chase roars through crowded Los Angeles streets. Best of all are the twists, turns and convolutions which Benson scatters throughout the narrative. It will take an astute reader, indeed, to anticipate the real story of Diane Boston’s early life.