This would be a bug. Let me know if this is a new save or from an older one. If it is a new save then I will do what I can to find and fix it.
Thanks for your answer, it was a new save.
Also, when choosing "I won't go to the party" to the mother (not a lie), the monologue about lying to the mother still happens.
EDIT: If I may give some feedback too:
I don't know how I feel about the direction the story is taking, I am only at the beginning, but I have no idea how it will evolve after this, and I have only tried one path so far, but.
-Viv discovers new things about herself and wants to be more assertive, and change things in her life, ok. That's why I made all the choices that would go in that direction.
-First step is simply to stop being a pushover and be more assertive, ok.
-Then changing her appearance, ok.
-Then being a little more dominant, ok.
But after the week with the mother, things escalate very quickly.
When she tries to be a top with Evelyne (and ends up being on top, but not a top), it gets her in an awkward position, then she tells Harper she's not into 50 shades of grey stuff.
One week with her mother later and she thinks she is a top dominatrix and every girl in the world should crawl on the floor and call her mistress.
I'm not a big fan of ellipses in the first place, but most of her changes before that event are a slow burn, she even tries to be a good person, and suddenly she becomes a bitch.
I have nothing against the main character getting more corrupted than the girls she tries to get, but the change is say too sudden in my opinion.
Though I'm curious about what would happen with different choices, but I'll try them when I'll be done with this playthrough.