Undercover Vices by Tori Scott
Approx. 45,040 words.
Published on June 9, 2011.
Reed Stevens, an undercover vice cop on assignment to crack down on the sex toy business, gets deeply involved with Cassie Mills, a secretary by day/sex toy party hostess by night. Neither knows exactly what the other one is up to until the night Reed is forced to arrest Cassie.
And then they learn they've been set up.