Mike is a lonely work at home computer programmer. One evening he finds an oddly promising ad for a sex toy online which promises the "Best Orgasm of Your Life." He purchases the toy on a whim and it over delivers on it's promise.
This is the second book to occur in The Symbiote universe.
10,000 word story. There is a detailed male to female transformation as well as a female to male transformation, not to mention tons of graphic sex.