It's Not Easy Being Mean, by Lisi Harrison
It's the seventh book in the series. It's great!


When alfa eighth grader Skye Hamilton hands alfa seventh grader Massie Block, along with many other girls, the puzzle to finding the key that unlocks the secret room at OCD, chaos is unleashed at the private school. Massie knows that she must find the key to the room, or she can kiss being alfa goodbye. But as one other girl seems to be getting closer, Massie must and will do whatever it takes to stay on top. But, what will it take?

Massie must search the matresses of many Briarwood boys to find the key. She uses her skills as alfa and the help of her friends to get into the boys rooms. But when their luck runs out, they must do the unthinkable to get what they want.

Lisi Harrison's website: http://www.lisiharrison.com/
Other books from the series:
1.The Clique* by Lisi Harrison
2.Best Friends for Never* by Lisi Harrison
3.Revenge of the Wanabes* by Lisi Harrison