OESD, overcards, and reads. Did I overthink this?

[Duerig]

Button in this hand sees around 40% of flops, and loves to bluff at scary rivers. However, ~2 hands ago I called his bluff HU on a 4 flush board with unimproved KK and took down the pot. He definitely is paying attention enough to remember who I am. On the turn, CO has 1.5 BB left, and as far as I know is generally very passive. How's my turn play?

Party Poker 1/2 Hold'em (9 max, 8 handed) converter

Preflop: Hero is UTG with A[img]/images/graemlins/club.gif[/img], Q[img]/images/graemlins/diamond.gif[/img].
<font color="#CC3333">Hero raises</font>, <font color="#666666">3 folds</font>, CO calls, Button calls, <font color="#666666">1 fold</font>, BB calls.

Flop: (8.50 SB) J[img]/images/graemlins/club.gif[/img], 9[img]/images/graemlins/diamond.gif[/img], T[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(4 players)</font>
BB checks, <font color="#CC3333">Hero bets</font>, <font color="#CC3333">CO raises</font>, Button calls, BB folds, <font color="#CC3333">Hero 3-bets</font>, CO calls, Button calls.

Since CO is passive I'm sure I'm behind here. But when he slows down, I'm pretty sure he's scared of what I'm holding.

Turn: (8.75 BB) 5[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets</font> ...

At this point, CO has 1.5 BBs left. I'm pretty sure he'll call if I bet, and he'll bet if checked too.

I figure if a bet is going in on the turn anyway, I might as well put it in myself to try to fold out the button and buy some outs. I know the button respects my bets / raises, but I have no idea how he feels about the CO.

Did I overthink this play?