"Of course you only came to Starbucks for food," Castiel said, smiling slightly. "Because that's what a sane, rational, fully awake person does, right?" He grinned at her as he spoke, clearly joking. Something he didn't usually do, because as a whole Castiel didn't understand joking. He was getting better, though. He blamed Balthazar and the Winchesters for that.
"I could not blame you for getting coffee for the walk home," he told her. "That's exactly what I'm planning on doing, personally."