Big Town — Doug J. Swanson

One libido-driven mistake, and Jack Flippo went from being a Dallas assistant DA to the kind of freelance snoop who hides in motel rooms with a tape recorder and camera. That's where he is one Friday night, waiting for millionaire Buddy George, Jr. to put the moves on a sweet young thing, when events turn unexpectedly violent.
Jack ends up in the middle of a dangerous, Texas-size mess of double and triple crosses. To save his skin, Jack knows he must outsmart Buddy's steamy assistant, Paula Fontaine. But when she uses a little liquor and a lot of sex to ensnare him in her web, Jack's not sure he's ever coming out alive.