Both are wrong. The girlfriend who doesn't resolve the misunderstanding right away. The boyfriend who doesn't end the relationship in a healthy way, without asking for explanations. They are young, it's understandable. What I don't understand is why in this chapter the ex-GF only teases without giving explanations. it is an unnatural reaction. I consider this chapter lazy writing. The author simply wants to carry on the same premise for several chapters, when in reality there is no real need. An explanation now would still have kept high the "drama level" that he needs.