Wicked Lovely by Melissa Marr

Ashling sees fairies. They are everywhere, causing trouble and playing pranks. She has carefully avoided their attention, fearing for her very life. But now, she can't. The summer king of the fairies is looking for the girl that will be his queen, give him power over winter and save his court. He thinks that is Ashling. While being courted by a king may be flattering, it is absolutely dangerous and it doesn't change Ashling's feeling for Seth, her long-time friend and now protector as she tries to avoid being sucked into the terrifying world of the faey.

This is an intense teen adventure and a "good read." However, the themes, language and situations make this a book best suited to older teens.