Sextortion by Ray Gordon
Ray returns with some summer fun, and his usual insight into the world of happy families. It's an old story. Man starting to be eclipsed by sudden bloom of his previously dull wife. She's suddenly sexy, successful and rich and he's 'the husband'. So he and his mistress, Crystal - very mistress-ly name that - plot their revenge (and a few kicks along the way). But as usual with our Mr. Gordon things don't turn out to be particularly straight-forward.