NL100 - Turn decision with overpair

[Conspiracy]

I have never played with villain before but he seems very donkish. He has been limping, minraising and 3x raising the button.

Earlier I 3betted him with KK and he called the flop bet with TP on a low board and then raised allin when he turned two pair.

What's the standardline here? b/f, b/c, c/c?

Full Tilt Poker - No Limit Hold'em Cash Game - $0.50/$1 Blinds - 2 Players - (LegoPoker Hand History Converter)

Hero (BB): $202.95
SB: $220.15

Preflop: Hero is dealt 9[img]/images/graemlins/diamond.gif[/img] 9[img]/images/graemlins/club.gif[/img] (2 Players)
<font color="red">SB raises to $3.00</font>, <font color="red">Hero raises to $11.00</font>, SB calls $8.00

Flop: ($22) 6[img]/images/graemlins/heart.gif[/img] 4[img]/images/graemlins/heart.gif[/img] 3[img]/images/graemlins/diamond.gif[/img] (2 Players)
<font color="red">Hero bets $18.00</font>, SB calls $18.00

Turn: ($58) 8[img]/images/graemlins/spade.gif[/img] (2 Players)
<font color="red">Hero ???