I'm really not sure how each one is determined, but just thinking that it may even go back to the Preps party, when Josy's arrives, did you go after Josy or Maya. Or any of the other little scenes where you choose one girl over the other.
On my thouple path I purposely chose Josy over Maya every time and ended up with the Josy scenes in ep11.
Thats the point, I kept balance between them. After the Preps party I went with Josy and later, when you have to choose whether go with Maya or Josy, I went with Maya. And after the Halloween party Josy stated that I spend equal amount of time with them. After that, during episode 10, you have to choose again to spend time with Maya or Josy, so I have two saves, one for each one of the girls.
But now in episode 11, the dates are with Maya in the two saved games. Which doesn't make any fucking sense because in each of the saves I've prioritized one girl over the other, at least after making the relationship official. Also, I think it's stupid not to put the option to choose which girl to go with as it happened until now and that the game does it automatically for who knows why.
You are supposed to be in a threesome, so it would be normal to spend time with both, or in the worst case to be able to choose who to be with depending on your tastes, not that the game does it automatically. In my case I prefer Josy, but I'm sorry I'm not going to play the whole game again just because of this. If the game has decided Maya, then so be it.
Which will lead me to think how poorly designed the Maya/Josy path is. In order to access Josy, it seems that you have to choose her all the time, and from the perspective of the story it doesn't make sense. During the previous chapters you spend a lot more time with Josy than with Maya. For example, Josy stays at your house after Maya's father visit. Then, after the HOT party there is also the option for you to end up in bed with her. And to finish you join the gym with her. Meanwhile, Maya hardly appears, and the only time you spend with her is at the dorm party and a little bit at the library. It is logical to make the dates with Maya to compensate, but now it turns out that the game automatically chooses one over the other just because of that.