Hardcore Gay Jerk Off porn books came about in the late 1960's.  A major producer and distributor of these books was a company called Star Distributors.

Star Distributors was a New York City-based adult book company that begun in 1971 by three men Robert "Dibi" DiBernardo, Theodore "Teddy" Rothstein, and Andrew "Andre" D'Apice. Star made and distributed 16mm and 8mm films, magazines and of course gay sex paperback books. Star made the best, the nastiest gay dirty story Jerk off books in the Adult Industry. I started purchasing from Star their first year in business. I knew Teddy and DiBi as well as Syd Levine, Phil Roberts and Mary Fried. It was somtime in 1986 that DiBi went missing, rumors started to fly. It was a while later that BiDI's body was discovered in a trunk of a car in the meadowlands of New Jersey.  For most of us in the Adult Industry it wasn't until John Gotti's trial (the New York Don of the Gambino crime family) that we knew why DiBi was killed.