Very strange 4-bet spot w/ 99 vs D_liciousUTB

[nextgenneo]

Main Vil is D_liciousUTB. I have him at 24/19/3 over a large sample and he folds his big blind 72% of the time. I have no direct history with him.

SB is a 50/8 party fish.

Party Poker, $2/$4 NL Hold'em Cash Game, 6 Players
LeggoPoker Hand History Converter

BB: $520
UTG: $442.30
MP: $577.40
CO: $551.34
Hero (BTN): $400
SB: $143.08

Pre-Flop: 9[img]/images/graemlins/heart.gif[/img] 9[img]/images/graemlins/diamond.gif[/img] dealt to Hero (BTN)
3 folds, <font color="red">Hero raises to $14</font>, SB calls $12, <font color="red">BB raises to $65</font>, <font color="red">Hero raises to $172</font>, SB folds, BB calls $107

<font color="blue">Obviously I don't 4bet here every time but once in a while vs these kinds of opponents I will 4bet and stack pre. Its a great spot pre for him to squeeze. His call though was WTF</font>

Flop: ($358) T[img]/images/graemlins/club.gif[/img] 2[img]/images/graemlins/spade.gif[/img] K[img]/images/graemlins/heart.gif[/img] (2 Players)
BB checks, Hero has $228 left

<font color="blue">Ummmmmm.... what can he have, he'd surely shove AK pre as most other hands. Was really lost at this point. Whats the plan if we check behind, or is this a good spot to shove?</font>