I'm not sure what I'm doing wrong. I'll play from the start, work Mikah's arousal to high, have one interraction and she will leave "for coffee" forever. I can then find a locked scene in the coffee shop but I find no way to get Mikah back to the house and this is before I've even unlocked a single ability.

Please tell me what I am doing wrong here?

Apologies for the late response! I've been having internet issues lately. 

Once a character enters the gangbang scene, they spiral out of control and will not return. The goal is to get all the women into a gangbang scene and that will trigger the win condition. I'm still working on a way to make this more apparent in-game.