Jade is a succubus enslaved to a demon, Kane. Rajahni is an incubus enslaved to the same demon. He learns of a way to break the bond by stealing four souls that match some latin? words on his bracelet or bond. They steal the souls when the body reaches it's climax. Shares this info with Jade since he is in deep puppy love with her. (view spoiler)[Turns out they were both sold to the demon by the same man, Luna. That's a problem since they both have to drink the soul of the person who got them their immortality. (hide spoiler)] 
 I read Hex Appeal which included a short, Cherry Kisses, from this series. Loved it so I picked this book up. Didn't even land in the same hemisphere as the short story. 
 It's a anemic list what I liked in this book. Let's start with that. The author has a brilliant handle on how to write the fire & brimstone demons. Unfortunately, we only get a small cameo of that at the end of the book. Kane was the only interesting character. Author failed to exploit that big time. 
 Not crazy about succubus stories to begin with. However, I'm willing to overlook certain things in a book if you give me a good story to focus on. This had very little back story, almost no world building and went from sex scene to sex scene. When the character, Jade, isn't having sex with someone she's thinking about it in great detail. 
 Maybe the sex slave situation isn't my thing, but this was just trashy. Don't even get me started on that ending. (end of the book spoiler)(view spoiler)[Turns out it was all for nothing. They would have had to steal the soul of someone they loved to break the bonds. That little catch 22 was a good plot twist. What I am steamed over is they do nothing after the fact. Do they kill kane? Try to find another way out? Nope. They just roll with it. Business as usual. (hide spoiler)] 
 May try the second book since it is a different cast of characters & doesn't revolve around succubi or incubi. It is a maybe the size of texas!