Bit: An Erotic Tale of Sex, Submission, and Zombies by Rynna Cress 
http://www.amazon.com/Bit-Submission-Zombies-Lesbian-ebook/dp/B007RQIP3E/ref=sr_1_1?s=books&ie=UTF8&qid=1340379873&sr=1-1&keywords=bit+by+rynna
ASIN B007RQIP3E
Story rating: 5 out of 5 paddles
Sting factor (kink): 5 out of 5
Blurb:
In a desolate, apocalyptic future, the dead walk amongst the living with a vicious hunger for flesh, and twin sisters Dana and Betsy are tired of running, tired of living in terror. When they hear a mysterious radio broadcast promising sanctuary, they dare to hope that they might have finally found a safe-haven. Instead, they discover a twisted, kinky nightmare that will push them to their limits and test their very will to survive.
Review:
Bit is the type of short story that takes you on one hell of a roller coaster ride. It starts out like a typical apocalyptic story where you might start to ask yourself if you have already read it. Then, it drops you down that first hill which lets you know if you’ve ever been on this ride before you’d damn well remember it. Spoiler alert– don’t read further if you like big surprises. This book kills off a main character, zombified another, and mixes up zombies and BDSM in one crazy ass kind of way, but it works. And, it’s a little surprising just how well it works.
Bit is the first zombie themed BDSM book I’ve read. I like to think of myself as a fan of zombies since I’ve seen almost every movie out there and watch Walking Dead every week when it’s on. The beginning has a scene with a an older couple with an RV that screamed Walking Dead to me, but I still liked it. When the zombies and BDSM came into play, goodness gracious. I don’t even want to tell you key elements because it will ruin it. But if you like zombies and you like BDSM you should check this out. Just keep your arms inside the ride until it comes to a complete stop.