FYI, there's an early instance when Mary goes to Vicky's room to talk with her that she refers to herself by Helena's title (i.e. "I've been a horrible stepaunt").
Also, after Vicky cums between Helena's thighs on that first night, she thinks to herself "I hope Mary doesn't notice" regardless of chosen relationship.
Another place is when Vicky checks Mary out in the kitchen: "I really didn't remember that Mary was so...sexy..." (again, ignoring all titles/relationships).
Personal opinion: I feel like Vicky, Melissa, and Cathy should refer to Robert by his title depending on what the player chooses at the start.
Overall, though, game has a ton of potential. Keep up the good work.