The Stargazer: The Arboretti Family Saga - Book One (Arboretti Family #1)
Michele Jaffe

Here's where the steamy part comes in to play. Ian, who had been deeply burned by his ex-flame Morgana da Gigio, can't help but feel attracted to his fake fiancée's beauty, but he refuses to acknowledge the pull she exerts on his heart. Bianca is eager to try out the knowledge she has gleaned from her prostitute friends, and Morgana, the beautiful ex, is using her sexual powers to manipulate everyone within reach of her perfume.
As Bianca closes in on the killer, Ian struggles with the battle between his head and his heart. Though their compatibility in bed is undeniable, the two's fragile bond is strained by the increasing dangers--explosions, more murders, seductions, executions, seven giants, and a dwarf flush out the mystery.