Showing Bad Business by Robert B. Parker

When Marlene Cowley hires Spenser to see if her husband, Trent, is cheating on her, he encounters more than he bargained for: Not only does he find a two-timing husband, but a second investigator as well, hired by the husband to look after his wife. As a result of their joint efforts, Spenser soon finds himself investigating both individual depravity and corporate corruption. It seems the folks in the Cowley's circle have become enamoured of radio talk-show host Darrin O'Mara, whose views on Courtly Love are clouding some already fuzzy minds with the notion of cross-connubial relationships. O'Mara's brand of sex therapy is unconventional at best, unlawful-and deadly-at worst. Then a murder at Kinergy, where Trent Cowley is CFO, sends Spenser in yet another direction. Apparently, the unfettered pursuit of profit has a price.