Network neutrality has recently been the topic of an important debate, in both the telecommunication and political worlds, because of its potential impact in every-day life. While there has been many studies discussing the advantages and drawbacks of neutrality, there is no game-theoretical study dealing with the observable situation of competitive ISPs in front of a (quasi-)monopolistic content provider (CP), while it is a complaint from ISPs, and an illustration of the non-neutrality need. This paper provides a first game-theoretical analysis of relations between two competitive ISPs and a single CP, in the form of a four-level game, played at different time scales. This game is analyzed by backward induction. We show that while the complaint from ISPs is relevant with a such a competitive model, inserting side payments does not solve the problem.