The river Donk

[PokerBob]

Canterbury 15/30 (9 handed)
BB here seems to be tight. I have yet to see him show down junk. He hasn't been too aggressive post-flop, but he seems to play OK.

one moron limps. I raise A [img]/images/graemlins/club.gif[/img]J [img]/images/graemlins/heart.gif[/img] in MP, one moron cold calls, BB calls.

Flop 4ways: K [img]/images/graemlins/heart.gif[/img]J [img]/images/graemlins/diamond.gif[/img]7 [img]/images/graemlins/club.gif[/img]

checks to me, I bet, MP folds, BB calls, limper folds.

Turn (HU): 4 [img]/images/graemlins/spade.gif[/img]
BB checks, I bet with that being the last one I put in unless i improve. BB calls.

River: A [img]/images/graemlins/spade.gif[/img]

BB bets, what's my plan?