99 against DONK

[Mercman572]

villain will call most raises preflop. had a hand against him where he bet .25 on flop and turn on a 4 flush and check/called K high on my river steal when the draw didn't get there. so i believe .25 is his standard drawing bet. thoughts?

Party Poker No-Limit Hold'em, $ BB (6 max, 5 handed) converter

SB ($20.90)
BB ($60.08)
UTG ($15.50)
MP ($36.50)
Hero ($29.55)

Preflop: Hero is Button with 9[img]/images/graemlins/heart.gif[/img], 9[img]/images/graemlins/club.gif[/img]. SB posts a blind of $0.10.
<font color="#666666">1 fold</font>, MP calls $0.25, <font color="#CC3333">Hero raises to $1.5</font>, SB (poster) calls $1.40, <font color="#666666">1 fold</font>, MP folds.

Flop: ($3.50) 4[img]/images/graemlins/club.gif[/img], K[img]/images/graemlins/diamond.gif[/img], 8[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">SB bets $0.25</font>, <font color="#CC3333">Hero raises to $3</font>, SB calls $2.75.

Turn: ($9.50) 4[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
SB checks, <font color="#CC3333">Hero bets $5</font>, SB calls $5.

River: ($19.50) T[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
SB calls $11.40 (All-In), Hero folds.

Final Pot: $30.90

I really think he caught trip 4s when he check/called turn. thoughts on the whole line?