Weekend Hand

[WiredPair]

$2-$5 in Colorado on Friday night. Sit down at a table that seems pretty loose. Lot of money around. Didn't get many hands until I was dealt KK on the button. UTG +1 calls, cutoff calls and I raise. BB comes along, UTG +1 and cutoff call.

Flop comes:
Q 8 2 (rainbow)

Checked around to me and I bet out. BB drops, UTG +1 and Cutoff call.

Turn comes: 8
Q 8 2 [8]

Checked around to me again. I bet. UTG +1 drops and cutoff calls.

River comes: 4
Q 8 2 8 [4]

Cutoff checks to me. I realize I have simply been betting my hand and haven't really stopped to think what he could have been calling with. In addition, I've seen this guy checkraise a few hands. I decide to check behind.

Results later. Any thoughts on the play of the hand? Thanks.