Quads Dilemma

[lennytheduck]

Before getting into the hand in question, and in turn the theory, I just want to make it clear that I'm aware this isn't a true high stakes hand but I felt like I would receive much better responses from the readers in this area of the forum that in small stakes.

I have been sitting at the table for a while and have been playing fairly wild, having to show down some winners that I would not like to be seen usually. UTG has been sitting almost the entire time I have but he bought in for the minimum and hasn't done much, therefore I have no read on him.

Onto the hand:

Poker Stars 1/2 NL

Hero UTG+1, ~350 behind, K [img]/images/graemlins/diamond.gif[/img]K [img]/images/graemlins/spade.gif[/img]
Villain UTG ~80 behind
BB has about 220 behind

UTG limps, Hero raises to $10 <font color="red"> </font> , BB calls 8, UTG calls 8

Pot = $31

FLOP: 5 [img]/images/graemlins/club.gif[/img]5 [img]/images/graemlins/spade.gif[/img]5 [img]/images/graemlins/heart.gif[/img]
BB checks, UTG checks, Hero checks

Turn: 7 [img]/images/graemlins/club.gif[/img]
BB checks, UTG checks, Hero bets $16 <font color="red"> </font> , BB folds, UTG calls $16

POT = 63 dollars

River: K [img]/images/graemlins/club.gif[/img]
UTG checks...

Now the thought has certainly entered my head that the villain might have the case 5, but I certainly am not going to give him much credit for it in this spot. I also thought AA was a possibility on an intended limpraise, but being as I was the raiser he may have thought he could extract the maximum from me by cashing in on my aggressiveness. Having made the lock on the river I think for a while and decide to put him in for his last ~$50.

My question(s) is this: What would your move be on the river in this situation and also in a situation where stack sizes were equal and/or he had me covered?

Comments on the preflop, flop and turn lines are also appreciated.