[kakakka]

I think Grodek offering his hands to Flit is some sort of trying to confirm if they are on the same level of understanding. Offering hand come off as, "I am formal with you on this, so I am talking to you like you are also an adult" kind of thing.

Thinking about it, there are other ways for this too, the "look directly to the eye" confirmation or the more cheesy "pinky wear" approach.