Sweetie Belle and Applebloom notice that Scootaloo has never invited them over to her house, and becomes unhappy when they mention sleeping over at her place. Well, they don't even know Scootaloo's parents!

Another question came to the minds of the two: Why does Scootaloo treat Big Macintosh and Fluttershy like parental figures?

They try to answer these questions, and end up learning a lot of new information that no one knows besides three ponies.