What makes you think you're the only "insider"?
I was thinking about it, in fact, I even predicted your comment. Thing is, so far, the MC has had a couple of delusional events, the last one being the art class fantasy where he fucks Elizabeth.
With Maki, she certainly had some exposure before, but that last sex scene is uncertain, MC was under the drug's influence at least slightly, and Maki wasn't behaving the way she usually does, not to mention the way that scene ended, so to me is more than likely that the MC is either dreaming or at least having a hallucination, so it doesn't really count towards her relationship going forwards, so I'll refrain from moving her upwards until I'm sure I'm wrong.