I only found the raws up to chapter 13, though I have seen excerpts of the scene you're no doubt talking about. Which chapter is it?
Edit: Nevermind.
Chapter 16. Ooooy boy. That was... close. Still, I'm afraid this story will take an ever darker turn soon enough, what with the new character that was introduced and how the heroine starting showing hints of yandereism.
Fuck, I regretted clicking the raws, now I saw a chapter that makes me even more curious than before, but I can't read it because I don't have an account.