Exactly! It would be adorable, in its total noncommunicativeness. And she would call him Takashi-kun.

(No, because Mori is 18. *laughing* And totally devoted elsewhere and without any shared history, and if Mustang even thought vaguely about considering maybe being jealous Hawkeye would just give him a ...seriously, sir? look. And then he would go "Heh." and say something smirky.)