Aziraphale excuses himself to the kitchen along with Greta, taking it open himself to prepare a bit of tea to go with the biscuits, or to settle his nerves. Either way. He feels anxious and he's not entirely certain why, whether it's eagerness to return home or concern about how Lilly is going to adapt - perhaps a bit of both.

As Greta brings the children some biscuits, Aziraphale pours them each a cup, and carries one out to her, hovering nearby, keeping a close eye on the girls. And maybe on the biscuits.