Hmm I wonder about this ex. He seems like a scumbag for sure, but I wonder if he got that way because he got "nagi'd"? Like, maybe he was a struggling artist like the MC, Nagi stalked/moved in with him, and he ended up becoming totally dependent and spoiled by her 'til she lost interest. Maybe this is gonna be a wake up call for MC, because she seems like she might be letting herself go down that path a little.
Yeah, I also see a pattern here. Maybe the bottom line will be that the MC realises she can't use Nagi as she pleases or else she might be left, too.
Also it's not wrong, that Nagi is a stalker, but smh it sounds so weird when she is called that in the manga. I mean she just cooks and takes care of the MC and knows everything about her. But she doesn't invade her privacy too much (I smh expected her to kneel before the key hole, when MC was bathing, good thing she didn't). So totally obsessed yes, but stalker?