Who played this worse

[colehard]

Not sure if my slow play was the worst mistake here..I was planning a flop check raise.

MP kept saying they were a bad player in chat and they did draw out on me twice when I was betting a decent % of the pot (once rivered a board str8 that matched my str8 for a split and once rivered top two pair to beat my flopped 2 pair)

Party Poker No-Limit Hold'em, $ BB (6 max, 6 handed) converter

Button ($36.53)
Hero ($27.6)
BB ($31.9)
UTG ($24.75)
MP ($51.05)
CO ($6.9)

Preflop: Hero is SB with 8[img]/images/graemlins/spade.gif[/img], 8[img]/images/graemlins/diamond.gif[/img]. Hero posts a blind of $0.1.
<font color="#666666">1 fold</font>, MP calls $0.25, <font color="#666666">1 fold</font>, Button calls $0.25, Hero (poster) completes, BB checks.

Flop: ($1) 9[img]/images/graemlins/club.gif[/img], 8[img]/images/graemlins/club.gif[/img], K[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(4 players)</font>
Hero checks, BB checks, MP checks, Button checks.

Turn: ($1) Q[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(4 players)</font>
<font color="#CC3333">Hero bets $2</font>, BB calls $2, MP calls $2, Button calls $2.

River: ($9) K[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(4 players)</font>

<font color="red"> Hero Bet $5 </font> BB Fold, MP raise $20, Button Fold, Hero???

Is this a slow played 2 pair often enough for me to fold? Or is this a str8 or trip kings often enough to call?