After going through the entire game again, I noticed a potential plot hole.
So, if you go through all the events with Fawn, you end up moving together with her, having a shared Condo and all.
That in itself still doesn't have any plot holes yet, but what if you invite Rinny on a Date after you moved in with Fawn? Because during said Date, it's described how you go to your Condo with the Succubus Girl to watch some movies.
Exactly, the same Condo you share with Fawn now.
I know it's asking much, paying attention to every detail and events in your game that get's bigger with each update and it's definetely too much to ask for you to "fix" that little plot hole.
I just wanted to mention it, because I found the notion of Fawn completely ignoring you bringing another girl over hillarious.
And who knows, maybe you get a new idea from this little thing I mentioned.