Wicked Lovely by Melissa Marr

Rule #3: Don't stare at invisible faeries.
Aislinn has always seen faeries. Powerful and dangerous, they walk hidden in the mortal world. Aislinn fears their cruelty - especially if they learn of her Sight - and wishes she were as blind to their presence as other teens.

Rule #2: Don't speak to invisible faeries.
Now faeries are stalking her. One of them, Keenan, who is equal parts terrifying and alluring, is trying to talk to her, asking questions Aislinn is afraid to answer.

Rule #1: Don't ever attract their attention.
But it's too late. Keenan is the Summer King, who has sought his queen for nine centuries. Without her, summer itself will perish. He is determined that Aislinn will become the Summer Queen at any cost — regardless of her plans or desires.

Suddenly none of the rules that have kept Aislinn safe are working anymore, and everything is on the line: her freedom; her best friend, Seth; her life; everything.

Faery intrigue, mortal love, and the clash of ancient rules and modern expectations swirl together in Melissa Marr's stunning twenty-first-century faery tale.