The Warlord's Concubine by J.E. Keep
The Warlord's Concubine is a hot read.
The storyline provides enough substance to keep you reading and enough conflict to keep it interesting. It's a erotic fantasy read, so there's little sense of realism; the author controls her world well and creates a strong visual setting.
I didn't especially bond well with the main character, Mirella, but I was interested enough to keep following. The spice level is definitely a 4, helping this book to be a 3.5 fairy read.
If you're looking for a short, spicy and quick read then most definitely check this one out.
The Warlord's Concubine