Derek was kind of used to coming home from work and spending time with Joy catering to Rachel in the evenings. That was different than when the weekend hit and his old patterns were completely out the window.
He was used to having the place mostly to himself on Saturdays because Joy worked then and then they usually went out to do something on Sundays for a few hours before coming home, doing various chores, and hanging out. It was weird having people here on Saturday but that wasn't all.
Rachel didn't particularly like going outside. It made her anxious and he couldn't blame her for that after being locked up for so long.
So they stayed inside. All day.
At least Joy got her some headphones for when she was watching videos trying to catch up and get ready for school in the fall so he didn't have to listen to that. She preferred doing it in the living room rather than their bedroom because she didn't like being alone.