Because she couldn't believe that they didn't do this years ago.

Because he cares about her, alot more than he should.

Because if he could do anything, he would kiss her.

Because he will do anything for her, even that mean die for her.
Because he love her and it's hard for both that they can't be together, because for that job.

Because he think she's a national treasure.

Because he was making up reasons for her to stay in 'Lost City'.

Because he knew.

Because he wishes there were two of her.