I think the logic with Bella is that they have been dancing around it for a couple of months and she isn't the type to accept someone she's serious with being out there fucking other people.
The main problem is the suggestion that you need to choose either Nicole or Lily and that Quinn want's you to keep it in your pants to be with her. (Even though she doesn't hold you to that). That only leaves
I think Chapter 10 would be the absolute latest you could make the split given that you need to have the good times, inevitable fight, breakup and reconciliation by episode 16. (Presuming that is when the game wraps up, if he makes a series 5 then the timeline changes and this feel like an even earlier path split)
I think Envy and Lily have a choice in this episode, though you might not be locked out of fucking around having taken it. There is also a soft lock on Quinn, which doesn’t matter as such, since you can still get her lewd scene, but she is pushing for MC to be exclusive. Rio doesn’t feel like she deserves a relationship and Cammy doesn’t want one because of the hooking so might take a while before they can be locked in. I think the only truly fuck around path is Sarah and Mel who really just seem to want to bone, and there are no developing feelings,
I would be surprised if every episode follows this format going forward. It won’t really make sense for Bella, or Jill (especially on her path) to turn up to lots of crazy DIK parties. We got the tease the next episode will take place at Christmas, however given the game is set in the US we should almost certainly have a thanksgiving event, and that also means 6-8 weeks of time have to pass between the end of the Halloween party and Christmas.
I’d guess we’ll get a party free roam or maybe even two (but different parties) making the most out of the party planner mini game. Meanwhile we’ll get more melodrama spread out over the new school term. Thinking about it‘s actually odd that we’ve just had the midterms and then he was teasing Christmas, given that we have the Nora is a teacher fall out to come.