KK HU overpair, lots of action NL100 (6max)

[sweet wicking action]

so, i've played a few hundred hands at this table, the SB has been there the entire time. he is playing something like 45/20/2, and is stuck for about 400. The rest of the table has been playing fairly passively before the flop, and i've been limping almost all of my hands, mostly in the hope that i'll limp a monster, and get heads up against the SB. If he had not kept reloading, I probably would have left the table. however, over the past hour or so, i had noticed him tightening up post flop a bit, and playing smarter. i'm fairly certain this is the first time i'd seen him bet call, and then bet, 3bet when heads up. certainly the first time against me. taking all this into account, does a fold here make me way too weak?


Party Poker No-Limit Hold'em, $1 BB (6 max, 5 handed) converter

Hero ($544.40)
MP ($169.42)
Button ($76.60)
SB ($120.45)
BB ($101.23)

Preflop: Hero is UTG with K[img]/images/graemlins/heart.gif[/img], K[img]/images/graemlins/spade.gif[/img].
Hero calls $1, <font color="#666666">1 fold</font>, Button calls $1, SB completes, BB checks.

Flop: ($4) 6[img]/images/graemlins/heart.gif[/img], 2[img]/images/graemlins/spade.gif[/img], 8[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(4 players)</font>
<font color="#CC3333">SB bets $4</font>, BB folds, <font color="#CC3333">Hero raises to $8</font>, Button folds, SB calls $4.

Turn: ($20) 4[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">SB bets $5</font>, <font color="#CC3333">Hero raises to $20</font>, <font color="#CC3333">SB raises to $111.45 (All-In)</font>, Hero ????