Yes it is Teen fiction but is there really a big difference between the Mickey Bolitar and Myron Bolitar series. There is some , but the stories are such a good read . Before these I was reading James Patterson's Alex Cross series. That couldn't be described as teen fiction but the "romantic" scenes are so pukeworthy and so clearly written by a man that has no idea I wish they had been excluded. In fact the more I think of Patterson the less I like hiw writing. He does write some very good bad guys but they are nearly always too perfect and alex Cross and his family are truly sickeningly sweet and unrealistic. I now wonder why I read them - probably because I bought them - The later books kept mentioning the make and model of the car that he was driving and how wonderful it was for a family in so many ways; without being too cynical if he wasn't paid a large sum of cash by Mercedes for that then he is an utter moron.
Back to the idea of teen fiction, there's an argument to say that most Sci-fi and Fantasy books are also teen fiction isn't there.
Is it just the lack of graphic sex paragraphs and the age of the central characters that make a book Teen fiction?