Hmmm i seriously doubt she will actually do something (real) with the friend, even if he does try to approach her she is more like a yandere so he would be in danger if he tries something like that. On the other side, if what she said was true, then it could be that she is traumatized and she starts crying and begging for help, almost broken and then the mc will come to help... i dont know, no matter how you look at it there is like 0% of a real ntr route to success considering how the story has been going. Then there is the possibility other people said that other girls start hitting on him and she will break, or go full yandere, or well, it could be that she starts crying and the friend comes to console her and boom ntr route with normal progression appears. Anyway, what most people want is to see her to have a mental break down after all what she has done to him, but some people want him to suffer since he is stupid, well yeah he is, i doubt the author cares about it, i mean, both of them are dumb as f*ck, they are perfect for each other