Cap preflop; cap the flop; bet the river?

[oxymoron]

MP3 = 58.7 VPIP; 1 PRF; .56 TAF about 90 hands
CO = 20.37/11/1.87 over 216 hands
SB = 26.75/8.81/3.46


Full Tilt Poker ($2/$4 Limit Hold'em) converter

Preflop: Hero is Button with A[img]/images/graemlins/spade.gif[/img], K[img]/images/graemlins/club.gif[/img].
MP2 folds, MP3 calls, <font color="#CC3333">CO raises</font>, <font color="#CC3333">Hero raises</font>, SB calls, BB folds, MP3 calls, CO calls.

SB thought for a little then calls before the timer runs out.

Flop: (16.5 SB) [3[img]/images/graemlins/heart.gif[/img], K[img]/images/graemlins/heart.gif[/img], 2[img]/images/graemlins/club.gif[/img]] <font color="#0000FF">(4 players)</font>
SB checks, MP3 checks, <font color="#CC3333">CO bets</font>, <font color="#CC3333">Hero raises</font>, SB calls, MP3 calls, <font color="#CC3333">CO raises</font>, <font color="#CC3333">Hero raises</font>, SB folds, MP3 calls, CO calls.

Turn: (19.25 BB) [3[img]/images/graemlins/heart.gif[/img], K[img]/images/graemlins/heart.gif[/img], 2[img]/images/graemlins/club.gif[/img], 6[img]/images/graemlins/heart.gif[/img]] <font color="#0000FF">(4 players)</font>
MP3 checks, CO checks, <font color="#CC3333">Hero bets</font>, MP3 calls, CO calls.

River: (22.25 BB) [3[img]/images/graemlins/heart.gif[/img], K[img]/images/graemlins/heart.gif[/img], 2[img]/images/graemlins/club.gif[/img], 6[img]/images/graemlins/heart.gif[/img], A[img]/images/graemlins/heart.gif[/img]] <font color="#0000FF">(4 players)</font>
MP3 checks, CO checks, Hero ???.

Not sure if I should bet here and hope that someone will fold a small [img]/images/graemlins/heart.gif[/img] or if I should just check behind and pray MHIG.

I don't mind so much that the donk is along for the ride because I've seen him call with air too many times. I called him down on an earlier hand with Q7o and my Q high won. When I'm not raised on the turn I think I'm good but I really don't like the final heart landing.