Pair of nines on low board vs LAG

[Khaos4k]

Villain is 58/44/1.5 over 60 hands. I checked river thinking I would induce a bluff....then started wondering what I actually beat.

PokerStars No-Limit Hold'em, $0.50 BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

Hero ($73.35)
BB ($72.20)
UTG ($62.45)
MP ($50)
CO ($52.85)
Button ($95.80)

Preflop: Hero is SB with 9[img]/images/graemlins/heart.gif[/img], 9[img]/images/graemlins/spade.gif[/img].
<font color="#666666">2 folds</font>, CO calls $0.50, <font color="#CC3333">Button raises to $2</font>, Hero calls $1.75, BB calls $1.50, CO folds.

Flop: ($6.50) 4[img]/images/graemlins/club.gif[/img], 5[img]/images/graemlins/club.gif[/img], 3[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
Hero checks, BB checks, <font color="#CC3333">Button bets $2.5</font>, <font color="#CC3333">Hero raises to $9</font>, BB folds, Button calls $6.50.

Turn: ($24.50) T[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets $15</font>, Button calls $15.

River: ($54.50) 6[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">Button bets $27.5</font>, Hero folds.

Final Pot: $54.50

[Quebecker]

a check mean weakness. Small bet the river and he will probably simply call. By checking, you show him your weakness and give him the opportunity to try to bluff you.

I really don't like the way you bet... you underbet, on the flop a 3,5$ to 5$ maybe should give you the information you wanted. I see the villain on a flush draw or he has the Aces and have is aces + gutshot straight draw.

I don't think the 6 of diamond on the river helped the villain.