There is probably a bug, because looks like switching her underwear is the only thing I can't do it right now, after a lot of sex scenes
Viewing post in Bottle Biosphere -Living with a runaway girl- comments
Well, it still doesn't work :/
Here, 3 save files to help you identify the bug. Last save from bit more future with dates etc.
https://fex.net/s/os6psda