After consummating yet another evening of compulsive sex – this night with the tall redhead who is Mattel’s top-secret voice of the first talking Barbie doll – Jack Ryan, the “Father of Barbie,” looks up at the oak ceiling of the boudoir in his Hefneresque Bel-Air Tudor mansion known as “The Castle,” turns to voluptuous, brown-eyed, breast-enhanced Gwen Florea, who, besides thrilling millions of little girls by having their favorite doll speak, helps run Mattel’s high-tech recording studio and acoustics lab, and says, “You know something, Kid, I should cut a hole in the ceiling so when I make love I can look up and see the stars and the moon. Wouldn’t that be just delightful?”

Even in bed, where he spends many evenings with one or more real-life beautiful dolls, most possessing the attributes of his fantasy doll, Barbie – the long-legged, slim-waisted, pointy-breasted, 11 1/2-inch plastic one that is making him a fortune – the Father of Barbie can always conjure up new ideas; the corny romantic bedroom sunroof is just one. He usually talks his ideas into a tape recorder he carries, or jots them down on a pad he keeps next to his toilet.

Ryan, a Yale-educated engineer who got his start making missiles for the Pentagon, had designed the original Barbie doll, which was released in 1959. While the doll and other iconic Mattel playthings he’s developed – Chatty Cathy, Ken, Hot Wheels, not to mention the Optigan musicmaker, among others – are earning him millions in royalties, his very favorite toy is The Castle. This private kingdom, on more than four acres of expensive turf, underscores the Father of Barbie’s hyperactive narcissism and singular quirkiness and eccentricity.

Literally following the old adage that “a man’s home is his castle,” Ryan transformed what had once been Bel-Air’s second oldest stately home, the staid (by Hollywood standards) 16,000-square-foot manse and grounds of silent-to-talkies Oscar winner Warner Baxter (who underwent a lobotomy to “cure” his arthritis and died not long after), into the Father of Barbie’s own private “once-upon-a-time” theme park.

There’s the high Greek Revival Moorish archway. There’s the wood bridge over the moat that protects the entrance. There are battlements. There are the massive arches guarded by knights in armor. There are the giant stone fireplaces, the leaded glass windows, and the rich wood paneling. There is the massive ballroom with marble floors. There’s the scallop-edged swimming pool with cabanas, and the open dance pavilion with a gazebo top. There’s the tennis court and tennis house (which often is home to one or more ladies of the moment). There’s the circular staircase leading to the tree house, which can serve eight under a chandelier.

The Tom Jones Room, in the lower level of the main house, is reserved for intimate Thursday night no-utensils dinner bacchanals at which the Father of Barbie presides from an enormous throne that once belonged to the Prince of Parma. (Ryan had originally bought the throne to cover the toilet where he jots his ideas, but it was disappointingly too big for the loo.) His Queen, a different beauty chosen each week, wears the crown used in commercials for Imperial Margarine.

During his lifetime, the Father of Barbie had his name on more than a thousand patents, and was a man of seemingly as many personas – inventor, designer, and serial Casanova, to name just a few. The Los Angeles Times once characterized him as “a strange mixture of the new technologist and the old playboy.” Zsa Zsa Gabor, the second of his five wives (he was the sixth of her nine husbands), had a somewhat different view. She described the Father of Barbie this way: “[M]y knight in shining armor, the inhabitant of a fairy-tale castle, Jack . . . was a full-blown seventies-style swinger into wife-swapping and sundry sexual pursuits as a way of life.” Most of her assessment was accurate, except for the wife-swapping part, unless she meant he swapped one old wife for one new one with rings and weddings, like she did with her mates.

Except for a small circle of confidantes, few knew that the Father of Barbie was a mass of treatable and untreatable emotional problems and addictions, including what later became known as hypersexuality, a manic need for sexual gratification, which was one of the symptoms of his bipolar disorder – a well-kept secret and an illness that explained his compulsive womanizing.

While most playboys used their proverbial Little Black Books to list the vital statistics and other intimate details about their women, the Father of Barbie’s method was far more advanced. He adopted the McBee Keysort System, used by librarians before the advent of small computers, to list the Barbie-like physical attributes and sometimes sexual interests and appetites of the women he knew. Most of that data was gathered at Hollywood parties and Beverly Hills society and charity functions. It was entered into the system by his coterie of beautiful social secretaries, such as statuesque Gun Sundberg, a former Miss Scandinavia, and Swedish Tanning Secrets TV commercial knockout.

Along with gathering all the details, his secretaries photographed certain guests and attached the prints to the data cards. The information in Ryan’s eight address books was also added to the mix. If the Father of Barbie required a statuesque Barbie doll lookalike with certain kinks for one of the Castle revels, or if he needed 60 chic couples for one of his enormous celebrity parties, his beautiful assistants had no problem gathering the precise card sort.

Whereas the Voice of Barbie was six-foot-one in heels, the Father of Barbie was a diminutive five-foot-eight – and that was in his custom-made elevator shoes imported from Church’s of London, which gave him at least three more inches. “My being taller than him was always something that he loved, like a real-life Barbie doll,” relates the Voice of Barbie. “He once said to me he loved me being tall so he could stick his nose in my boobs when he hugged me.”

Despite his success in bedding a chorus line of beauties, the Father of Barbie was no handsome Ken (the boy doll developed by Ryan and his crack team of Mattel designers and engineers that was brilliantly promoted as Barbie’s main squeeze). Besides Jack Ryan’s height, or lack thereof, his hair was cut and dyed an odd orange-red by famed “stylist to the stars” Jay Sebring; his speaking voice sounded as if he had inhaled laughing gas; his forehead was overly large and alien-like; he had a Humpty Dumpty build – his chest puffed out like a rooster in heat and he had skinny arms and spindly legs; and his complexion was a Bela Lugosi-like pale because of his genetic Irish-American pallor as well as the fact that he rarely ventured into the southern California sun.

A dandy of sorts, he sported custom-tailored suits from Mr. Guy in Beverly Hills, wore safari jackets with a silk ascot, and often arrived at a party wearing a full-length fur coat. Many considered him a blast, while others thought he was Napoleonic – in size and demeanor. His IQ was in the genius range.

Ryan’s role in the invention of one of the world’s most popular toys has been overshadowed by his bosses at the time – and Mattel’s official history of the doll. But 50 years after Barbie’s introduction, his personality seems large enough to survive the revisionists.

As Ryan himself said, “I designed the Barbie doll – if that’s any claim to fame. But at least it shows some kind of interest in art, or in women.”

Excerpted with permission from “Toy Monster: The Big, Bad World of Mattel” by Jerry Oppenheimer (Wiley), out this week.