I definitely would make sure to progress the bathtub scenes, ofc, since I find them very steamy. But I don't see anything (unless I'm missing something) requiring that they happen before progressing at night. I'm sure there are things I've still missed, although it
looks like I'm at least very close to complete through current content. A couple of things to remember also:
Just FYI, here are all of the fantasies when unlocked:
I can try to help if anyone gets stuck, although I don't have a lot of time these days, so I might be delayed in replying here.