King-high flush vs angry table coach

[deathpotato]

CO had been ragging on a fish about drawing out on him (it wasn't even much of a suckout) and I had managed to get him pretty angry by defending the fish's play etc. Up till now CO had been decent, if a little loose, but far from hyper-aggressive.

Paradise Poker 1/2 Hold'em (9 handed) converter

Preflop: Hero is BB with K[img]/images/graemlins/club.gif[/img], 8[img]/images/graemlins/club.gif[/img].
<font color="#666666">1 fold</font>, UTG+1 calls, <font color="#666666">1 fold</font>, MP2 calls, MP3 calls, CO calls, <font color="#666666">2 folds</font>, Hero checks.

Flop: (5.50 SB) 8[img]/images/graemlins/heart.gif[/img], 6[img]/images/graemlins/club.gif[/img], 3[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(5 players)</font>
<font color="#CC3333">Hero bets</font>, UTG+1 folds, MP2 calls, MP3 calls, CO calls.

Turn: (4.75 BB) Q[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(4 players)</font>
<font color="#CC3333">Hero bets</font>, MP2 folds, MP3 folds, <font color="#CC3333">CO raises</font>, <font color="#CC3333">Hero 3-bets</font>, <font color="#CC3333">CO caps</font>, Hero calls.

On the turn I put him on a flush, 66, 33, 88, and maybe two-pair. Turn play looks seemed straightforward with the 2nd nut flush.

River: (12.75 BB) T[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets</font>, <font color="#CC3333">CO raises</font>, <font color="#CC3333">Hero 3-bets</font>, <font color="#CC3333">CO caps</font>, Hero calls.

On the river I'm getting nervous about the ace flush, but I there was a better chance that he was going nuts with a set or a smaller flush than that he had the ace flush. If he hadn't been so angry, I might have slowed down (is this right?), but as it stood I thought he could very well just be tilting away.

Final Pot: 20.75 BB

This hand was interesting for me because it brought up the question of what to do with an opponent who you suspect has just started tilting, and who might think you're trying to get into a pissing contest with him. Given the good chance that he is tilting here, is my play alright? Thanks in advance, comments/questions on all streets very much appreciated.

[Sykes]

I think this is a no-brainer cap river bet. Unless you are 100% sure your opponet always has the Ace high flush, I wouldn't 3-bet. But knowing that your opponet is slightly tilting, this is a cap river bet all the time.

[Shillx]

The correct play is almost surely to check/raise the river and call a 3-bet. You lose if it gets capped and that is just 1 BB down the drain. If there was a 5-bet cap then the correct play would be to lead/3-bet and call a 4-bet. Getting a street capped w/o the nuts (when the nuts is something as broad as a nut flush where there are tons of combos) is almost always -EV. If you have something like KK on a KTT43 board (only one combo of TT beats you) then you should be going for a cap. With the 2nd nut flush, it is much more likely that the nuts are out agianst you here.

Brad