Prelude To A Fantasy (Harmless #7.5) by Melissa Schroeder

A really short story about Maura & Zeke's first time together.  It was hinted at in A Little Harmless Lie and actually this story takes place at that time.

Zeke has been half in love with Maura forever but she is his best friend and business partner Conner's baby sister.  Plus she is exploring her sexuality and thinks she may be into BDSM which Zeke doesn't do. But heading back to the hotel after a visit to Rough & Ready (a Hawaiian BDSM club) on assignment Maura pushes every hot button and Zeke finally gives in and makes love to her.  His heart is engaged and even though he knows it may not last he can't deny himself this taste of Maura.  Their story is continued in A Little Harmless Fantasy.