I hate the way I played this hand. Villain was slightly loose (VP$IP about 24%) and semi aggressive. I put him on KQ or KJ on the flop but since he only min raised me, I took one off. I read his bet on the turn as he didn't like the Q but had to keep betting. Should I have bet out the river and fold to a raise? How wrong did I play this?

Party Poker No-Limit Hold'em, $0.5 BB (10 handed)

SB ($53.2)
Hero ($52.95)
UTG ($52.35)
UTG+1 ($97.75)
UTG+2 ($45.65)
MP1 ($50)
MP2 ($25)
MP3 ($51)
CO ($46.75)
Button ($59.45)

Preflop: Hero is BB with , . MP2 posts a blind of $0.5.
4 folds, MP2 (poster) checks, MP3 calls $0.50, CO calls $0.50, 2 folds, Hero checks.

Flop: ($2.25) , , (4 players)
Hero bets $2, MP2 folds, MP3 folds, CO raises to $4, Hero calls $2.

Turn: ($10.25) (2 players)
Hero checks, CO bets $4, Hero calls $4.

River: ($18.25) (2 players)
Hero checks, CO checks.

Final Pot: $18.25

Results in white below:
Hero has As Kh (straight, ace high).
CO has Kc Jh (two pair, kings and queens).
Outcome: Hero wins $18.25.