>>41995879Harmony doesn't have her own mind and is instead the product of the connection between two. If mom could read their thoughts she would be able to notice when the thoughts in one of the twins start to only make sense when combined with the other, but mom isn't good enough. They are always talking, and telling when they pass the threshold and become Harmony is very difficult, especially when they are trying to hide their thoughts so they can chose their own presents. Harmony already know exactly what they want, but picking their own stuff out is more fun.
David is too young to realize there's anything strange about it, and doesn't know he's adopted yet. Hopefully they can break the news that he's adopted before he realizes it's biologically impossible for him to be related.