Nerd girl

It's about a popular guy who falls for a girl that's in a nerdy group, she's gorgeous, but nobody likes her because she isn't popular..
The popular guy named Dillion ends up being partners with the nerd of the class in 3rd period..
Katherine is nice, she's beautiful and can't put up with the bullies, they don't make fun of her looks, they make fun of her bc of her group, and who she hangs out with..
Does she snap?
Or does Dillion take up for her?
BTW THIS BOOK CAN GET VERY SEXUAL