A nostalgic grin—they'd commiserated over their muggle roots, somewhat in secret, not just because of anti-muggle hostility, but sometimes just (from the likes of Sirius) dismissiveness.

His expression flickered, almost shy, making him suddenly look twenty years younger. He put his hand over hers on his face, and it warmed his gaze on her until they could have been schoolmates again. He squeezed her fingers, then turned and got to work; using nonverbal and wandless magic and good old analog walking and picking up, to gather belongings for a trip.