Decision in an aggro game with an aggro pot

[sfer]

10 handed 50/100 on the old skins. Unknown CO has posted a dead SB and a BB. Folds to the CO who raises, I 3-bet on the button with K [img]/images/graemlins/spade.gif[/img] T [img]/images/graemlins/diamond.gif[/img], a loose SB donkey calls, a tight/tricky BB calls, CO folds. I'm playing with a recently changed screenname and this is my second orbit so the BB probably doesn't recognize me. 3 players, 11.5 SBs.

Flop is K [img]/images/graemlins/heart.gif[/img] J [img]/images/graemlins/heart.gif[/img] 5 [img]/images/graemlins/spade.gif[/img]. SB checks, BB bets, I raise, SB folds, BB 3-bets, I call.

HU for 8+ BBs. Turn is the 4 [img]/images/graemlins/spade.gif[/img]. BB bets, what's my action?