KK in Middle/Late - flop/river questions

[Tim H]

Probably standard - 15/30 ten handed
hero is in middle/late with KK with the K of spades

UTG raises, Fold, Call, Call, Call, I reraise, Fold, Fold,
Both blinds call and everyone else calls.

7 to flop, me no likey for $277

Flop: 7c 5s 2s
Checked to me as last to act. I check - standard?
$277 in pot

Turn: 7s
BB bets, UTG calls and I raises everyone folds except BB and UTG who call
$457 in pot

River: 5d
Checks to me. I ??

My main question is do I bet the river? Looking at the hand after ... UTG probably would of have called a bet with AJos, BB would of folded with 44.