Tired of always being a good girl, Emma Baker wants to shed her goodie two shoes image and let loose her naughty side at a holiday costume party. Her plan backfires when she finds herself in the arms of the guy she secretly loved in high school and who refuses to give her one night of unbridled sex. Cameron “Cam” Fletcher has just returned from his second tour in Iraq and wants to put the war behind him and clear his mind with some hot, anonymous sex. When the lover he unmasks at the Christmas party turns out to be his best friend’s little sister, he is shocked and decides they should both forget anything ever happened. Will Emma convince Cam that being his best friend’s little sister doesn’t really matter and that she can truly be an awful good girl in his arms?