To be honest, for me it is very hard to get that threesome scene.
Whether Foxxxy or Chica get in too early, never both at the same time.
Sometimes I get hacked at the worst time or Frederika decides to stay the whole time in front of the door instead of just going away opon closing it...
I don't think there are any possible hints, are there?
You could remember the time when they start moving, the hacking is not always at the same time I think. Then it is random if Chica or/and Frederika go directly to me or not.
You could try to hold Foxxxy on edge, but if something time consuming appears (Bonnie or Frederika) then it might be over.
Chances are higher on hard, because her tempter is smaller and Chica starts to move sooner (0:00), but again, often are Frederika or Bonnie in the way...
Edit:
Again, Foxxxy was on edge, Bonnie started hacking and I stopped it just a bit before 0:00, then Chica and Frederika moved, Frederika didn't come luckily, but Chica moved only to the counter. Frederika came close, but to the other room. I looked away and Chica seemed to have moved from the counter to the door. Foxxxy started too rage and again too early...
There should be an easier way of getting the threesome, because Chica and Foxxxy always come through the left door. I think it would be way easier if Chica went to the right door, and as soon as Foxxxy stands before the left one, which you need to close, Chica would come from the right and the threesome would initiate.
Edit:
And another worst case scenario. Nothing happened before 0:00, then Chica and Frederika moved to the direction of the right door. Frederika came in front of the right door, and what I mean with worst case scenario, she didn't move away again, so Bonnie started hacking and Foxxxy came through the left door.
That could be another chance for the threesome, while Frederika occupies the right door, Chica could sneak to the left one and Foxxxy could start coming.
Or an opportunity for a threesome with Frederika.
Edit:
What is worse than a worst case scenario? When Chica doesn't even go to the left door...
Edit:
Like, how good must that timing be in order to work? Foxy just dashed through her window, was approaching, and then the Chica only ending...
Help???
This was the closest I could get to...
Edit:
Nevermind... FINALLY (I needed literally hours for it to work)