Yep. He's furious with her. Annie is completely convinced at this point.

Annie's expecting him to return a few minutes later, but she's surprised when it's nearly a whole hour later that he arrives. But she still accepts the coffee, and starts to pour sugar into hers. She likes it sweet, to no one's surprise. Finnick's sweet-tooth had rubbed off on her.

"Lots of sugar," she tells him. "And, ah, I can't pronounce it?" She gestures to the book that had a description and illustration of the fae and a highly unpronounceable name.