Who knew Barbie and Ken had such interesting sex lives?

There's a new book out that chronicles the kinky life and times of the toy designer who came up with the plastic playthings.

Yale-educated designer Jack Ryan, who started his career as a missile engineer at the Pentagon, was a "full-blown seventies-style swinger" with "a manic need for sexual gratification," author Jerry Oppenheimer says.

Oppenheimer's "Toy Monster: The Big, Bad World of Mattel" delves into the Bel-Air-based Ryan's orgies, marriages (including one to nine-times-betrothed Zsa Zsa Gabor) and inspirations for the iconic Barbie and Ken dolls.

Barbie and Ken through the years.

The author quotes Ryan's friend Steven Gnass saying, "When Jack talked about creating Barbie . . . it was ... almost like listening to a sexual pervert."

Apparently Ryan liked busty Barbie clones (go figure), and one who became the "voice of Barbie" in a line of talking dolls noted: "He once said to me he loved me being tall so he could stick his nose in my boobs when he hugged me."

But busty blondes weren't Ryan's only inspiration. The names Barbie and Ken came from two of Mattel founders Ruth and Elliot Handler's kids.

Despite marrying and having three kids himself, Ryan turned out to be a closeted homosexual; he died of AIDS in 1994.

One more thing: That marriage to Zsa Zsa? Apparently, when it was going south, Ryan disassembled Gabor's Rolls Royce and refused to put it back together again.

A complex man, to say the least.

For more on "Toy Monster: The Big, Bad World of Mattel" go to NYPost.com.