The Alpha by Annie Nicholas

BLURB:

Someone is about to get some Spice in his life.

Spice has nothing but the clothes on her back when she returns to Chicago. She's looking for a better life, and that means reuniting with her estranged twin sister, Sugar. She isn't thrilled to find out Sugar's boyfriend is a vampire. But then she meets Eric, once the bottle-cap-glasses wearing nerd next door - now grown into the kind of man she'd love to snuggle with on this cold winter night...and he's offered her his room in Sugar's hou...