KK playalong

[HoldEmNewby]

Villain runs at 18/10/2 he's got a WTSD of 25 and a WSD of 50. Whats the move on the turn and why?

Party Poker - No Limit Hold'em Cash Game - $0.25/$0.50 Blinds - 6 Players - (LegoPoker Hand History Converter)

SB: $41.89
BB: $45.31
UTG: $45.69
MP: $123.24
Hero (CO): $49.90
BTN: $49.00

Preflop: Hero is dealt K[img]/images/graemlins/diamond.gif[/img] K[img]/images/graemlins/heart.gif[/img] (6 Players)
2 folds, <font color="red">Hero raises to $2.00</font>, BTN calls $2.00, 2 folds

Flop: ($4.75) 9[img]/images/graemlins/spade.gif[/img] 5[img]/images/graemlins/club.gif[/img] 2[img]/images/graemlins/heart.gif[/img] (2 Players)
<font color="red">Hero bets $4.00</font>, BTN calls $4.00

Turn: ($12.75) 5[img]/images/graemlins/spade.gif[/img] (2 Players)
Hero??