Bella's pregnancy is only available on her romance route. As for the dance instructor, I really liked her too, but I could never find a good way to integrate a lewd scene with her that fit the story.
The instructed would have to dance with Max to show Liz how it's done. And then fall for him and change numbers. Or she could come back while Max is fooling around with Liz and ask if she can join, but that might feel a bit too off.