Cuck Club by T. H. Barker
Approx. 189,090 words.
Published on November 29, 2013.
ADULT CONTENT! Ned's wife Diane put John in an embarrassing position by coming on to him, but when John approached Ned about it, he discovered that Ned had his own reasons for encouraging John -- and so did Diane. Things moved rapidly in directions that none of them expected -- and they kept escalating. Soon Ned and Diane were telling others about John's talents -- and John was branching out...