[Everything these two do with each other is automatic, like this. Katsuki takes the drink back without feeling the need to say thank you. Taking a drink from it to quench his thirst a little before he replies.]

I've been doin' plenty of Quests even with my fucked up arm! I ain't letting a stupid injury stop me from being a Hero!

[Katsuki almost seems offended that Izuku would suggest they look only after he gets his automail. He can do battles with one arm!!!]

But I know shit will get done a lot quicker if I let you tag along and help. And I'm really gonna need it after I get that damn arm installed.

[He's both excited and dreading it...]

I heard it's gonna hurt like a bitch and take a while for me to get used to.