Quote Originally Posted by Buffalobiian View Post
Kirito has a harem but is embarrassed when Klein calls him out on it.
This.

The situation was that all the girls were glaring at him, making him uncomfortable, and then Klein was being snarky.

He was making fun of the emotional minefield that Kirito is forced to constantly navigate, WHILE he's in the middle of trying navigating it. A comedy kick to the face is appropriate.