You see, the king is actually a pretty strong piece, if used correctly.
It is a risky option to bring it out early in the game, but the rewards are sometimes worth it.
Normally however people do not move the king repeatedly. (So it could be possible that he is just showing off).
I played a guy today that played 1. f3 and the followed up with 2. Kf2. Not sure what he was doing but he just kept shifting his king around while I developed and then all the sudden started playing really smart moves. The game ended in a draw. I have had opponents do this before. Are they trying to show off or something? I'm so good that I can ignore principles and all that silly tempo stuff and you still can't beat me?