He's shocked at her approach, yet in some ways it seems like it's meant to be for him to encounter her here, and when she speaks he lets his face settle into a pleased smile. Who cares about the impossibilities when it's been so long since they last spoke? Acting like this is normal and to be expected seems to be the tactic she's taking, and so he goes along with that. "Well, I still think I'll be reading the labels on things before I swallow. You got a favorite here?"