i dont really get the harem comments either, he sticks with Asuna who turns out to be mildly crazy, his cousin-sister wanted his big digital dick until she found out who he was then was pretty shocked, Sinon was quite close during the events of GGO but after that she spends her time hanging around with Asuna and the rest of them while Kirito mooches around by himself.

If anything, Asuna is the one with the harem, Progressive even gave us a new character that was on her proverbial dick from day one.