"Stay" by Deb Caletti

Clara Pea's what her father likes to call her. She seems like such an easy going girl, but she has secrets. Lots of them. Including the secret where she finds that the boy she is "falling in love with", named Christian, is obsessive. I think that Clara should have taken this hint when she saw how he kept things like old papers from when he was in fifth grade on the floor of  his closet. Clearly, he couldn't part with things easily.
Christian has low self esteem, as well as high worries that he might lose Clara. I think because of this, its when he gets paranoid about what she wears, where she looks, whether she picks up the phone the first time he calls, and just staying in contact all the time. If I were Clara, the first time Christian started to act like that, i would probably break up with him!
Also, it doesn't help that there had been a murder years back. They were a couple simply sitting at a lake, when he sliced open her throat. Clara's father has made it clear what he thinks: the boy was obsessed with the girl, the girl tried to break up with him-then BOOM. There you have yourself a dead girl. Clara's dad just doesn't want that to happen to his daughter, is all.
If only Christian would understand...