Richelle Mead 
Succubus Revealed 

Georgina Kincaid has had an eternity to figure out the opposite sex, but sometimes they still surprise her. Take Seth Mortensen. The man has risked his soul to become Georgina’s boyfriend. Still, with Lucifer for a boss, Georgina can’t just hang up her killer heels and settle down to domestic bliss. In fact, she’s being forced to transfer operations…to Las Vegas.The City of Sin is a dream gig for a succubus, but Georgina’s allies are suspicious. Why are the powers-that-be so eager to get her away from Seattle – and from Seth? Georgina is one of Hell’s most valuable assets, but if there’s any way out of the succubus business she plans to take it – no matter how much roadkill she leaves behind. She just hopes the casualties won’t include the one man she’s risking everything for…