$400nl: QQ on rag board- kinda weird action by villan

[snowbank]

I have $490, villan covers.

I raise utg with QQ, and villan calls from button.

Flop: 6h8d4s

I bet about 2/3 pot, he calls.

Turn: 3h

I fire again, he calls.

River: 2c

I bet $140, and he pushes. I've got about $220 left.

villans been at the table for a while and we haven't really tangled much. i've been winning most of the pots we've been involved together in, most on flop or turn. i wouldn't say i've been bullying him though, so i don't think he's on any kind of tilt. he seems okay.

wtf can he have here? 5-7 i guess, but i didn't really put him on that.