Why she required a meal he didn't know, but he wasn't about to ask either. In many ways, Castiel suspected Dean would like her. Or perhaps Sam would. After observing the Winchesters for a little over four years, he knew their vices well. It didn't even occur to Castiel that she might have been flirting with him, so he said nothing more on the subject.
Then she said he was 'funny.' Humans often found him humourous, yet he knew not why. Few things he said were meant for comedic effect seeing as he'd never had Uriel's wit. However, she said it with genuine sincerity, so he took no affront.
"It was not intentional, but thank-you," he said politely. "I will...keep in touch. If there is nothing else you know, I must be going."