The bathroom is accessed via the living room, and is unlocked by progressing Pixie's storyline up to her "bath" event. It's her second event in Act Two, if I remember correctly :)
As for milf scenes, my focus at the moment is progressing the remaining Main Girl storylines and the main story points, but I usually try to work in other events and characters if I have time, so I can't say for sure but possibly! Definitely not in the next update though (I release weekly, so this week's update is almost ready to compile)