3bet this turn on draw?

[veganmav]

CO is a good tight player. He'splays and beats the 15/30 too. He is 16/9/1.3.
So he's not too agressive post flop, but still wins.

Party Poker 10/20 Hold'em (10 handed) converter

Preflop: Hero is SB with K[img]/images/graemlins/diamond.gif[/img], A[img]/images/graemlins/diamond.gif[/img].
UTG calls, <font color="#666666">3 folds</font>, MP2 calls, MP3 calls, <font color="#CC3333">CO raises</font>, <font color="#666666">1 fold</font>, <font color="#CC3333">Hero 3-bets</font>, <font color="#666666">1 fold</font>, UTG calls, MP2 calls, MP3 folds, <font color="#CC3333">CO caps</font>, Hero calls, UTG calls, MP2 calls.

Flop: (18 SB) 2[img]/images/graemlins/club.gif[/img], 7[img]/images/graemlins/diamond.gif[/img], 5[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(4 players)</font>
<font color="#CC3333">Hero bets</font>, <font color="#CC3333">UTG raises</font>, MP2 calls, <font color="#CC3333">CO 3-bets</font>, <font color="#CC3333">Hero caps</font>, UTG calls, MP2 calls, CO calls.

Turn: (17 BB) 8[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(4 players)</font>
<font color="#CC3333">Hero bets</font>, UTG calls, MP2 calls, <font color="#CC3333">CO raises</font>, Hero calls, UTG calls, MP2 calls.


So I think the flop cap is fine, everyone agree?
On the turn how does 3betting look? I didn't like it.
The CO probably has a high PP, so I could have lots of outs if he has something like QQ. Although mathematically speaking it's probably more likely that CO has QQ since I have one A and one K, in terms of action so far, he has played it more like AA, showing aggression every time possible. Anyway is anyone 3betting this turn? and why?