50NL - AK multiway drawy flop

BB is a 15/13 reg I have a lot of history with. He 4bet me bvb and folded to my shove a few hands earlier. Button is a 29/16

What's our turn line here? Should we check and try to keep the pot small or keep firing? If we're betting, whats an optimal size?

Full Tilt No-Limit Hold'em, $0.50 BB (9 handed) - Full-Tilt Converter Tool from FlopTurnRiver.com

saw flop

CO ($76.05)
Button ($39.25)
SB ($33.75)
BB ($50)
Hero (UTG) ($66.05)
UTG+1 ($50)
MP1 ($19.25)
MP2 ($50)
MP3 ($15)

Preflop: Hero is UTG with K, A
Hero bets $1.75, 5 folds, Button calls $1.75, 1 fold, BB calls $1.25

Flop: ($5.50) Q, K, 9 (3 players)
BB checks, Hero bets $3.50, Button calls $3.50, BB calls $3.50

Turn: ($16) 7 (3 players)
BB checks, Hero?

Bet, BB almost never has us beat and we want to charge his draws/ more importantly get value from the button.

hows 10-12 and fold to shove from BB? what if button shoves?

I'd just b/f $12 regardless of who shoves

I'm kind of torn between check and $8