in underfell AU, Fell sans invited you to his house so that you can meet his older sister Estelle for the first time. fell Papyrus was not happy of this, he didn't like his sister. right now you were sitting at the dinner table with fell sans and fell papyrus waiting for Estelle. the skeleton brothers were waiting patiently until you all heard a key and the front door opening as a skeleton girl walked in through the door. you assumed she should be Estelle. as soon as she enters Papyrus mutters something to himself quietly with annoyance.