He wanted to say that it was pretty, that it suited her, or some other compliment, but the way she responded told him exactly where it had come from and the the words died before they had a chance to be spoken. Rival! "...oh." If it hadn't been for the fact that she'd mentioned her birthday, he'd have never known at all while Naruto would've still remembered.
"Out of curiosity," he began, turning to face her, "how are you with handling awkward situations? In general, that is." The answer to that question was of the utmost importance to him. It would serve to dictate whether or not he finally gave in and let her repair that wing, whether or not he kept contact with her to "strictly business"... and whether or not he made it a point to avoid her entirely.