During this scene, when Korra says ‘Admit it, you like me’; he has to turn away. He can’t look her in the face as he lies, as most people can’t.
Which makes this a lot sweeter, in my opinion.
That scene was kind of a dead give away he felt something for her. If not then he would have kept eye contact during the fight.
((GIF isn’t mine. I don’t know who it belongs too or else I’d have it linked. Sorry.))