Wicked Wings by Elizabeth Briggs

They think I’m half angel and half human. They think I have no magic. They think because I grew up in the human world I’m clueless about what to expect at Seraphim Academy.
They’re wrong.
I’m not half human, I’m half demon — and this little succubus has come to play.
My brother vanished from Seraphim Academy without a trace, and I’ll do whatever it takes to find him, including infiltrating the school myself.
Even if it means going up against my brother’s best friends, who know something about his disappearance and aren’t talking. They may be angel royalty, but if they think they can intimidate me into leaving the school, they’re wrong.
There’s also the problem of the delicious professor who knows my secret. He’s hiding something too, and I’m going to find out what it is.
But I’ll have to be careful, because if anyone finds out I’m part demon? I won’t just get kicked out of Seraphim Academy — I’ll be dead.