For their tenth birthday, Stiles had gotten Allison a mug from a kiosk at the mall with AREN’T YOU GLAD WE EVOLVED OUT OF NEIGHBORING CELLS on one side and a picture from their school trip to the zoo, the one where Allison was hitting a goat trying to eat Stiles’ shirt, on the other. It’s such a metaphor for their entire existence that Allison puts it on the mantle of every subsequent house that they live in, next to their parents’ wedding portrait.