This takes place in Wave arc, I belive. Kakashi is possessive/Protective of naruto. I can't recall if it was fem naru or not as I do read both. What I do remember is that it was stated the reason there was one girl on each genin team was for them to be used for sex. Kakashi uses Sakura surfing wave and she is planning in her head how to marry him for prosteige because of the Hatake name. The enitre time they are having sex Kakashi can only think about how he can't wait for Naruto to be older as he is too innocent (or something like that). Though he later regrets using Sakura as he feels he has cheated on Naruto? Anyway he thinks of Naruto as innocent and Sakura as a slut.
Does this ring any bells with anyone? Please help me find this.