Nut flush on paired board

[restless]

Ok, I'm pretty new to 2/4 (200 hands...) so I guess I'm questioning my plays and analysing a lot more than usual. I also find 2/4 quite different from 1/2, hence my insecurity.

MP2 - Tight/Weak
CO - Ultra Loose (~90%). Not much PF raising. Calls ANY bets with ANY piece of the board. Regardless of previous action and board texture. Only raises with strong hands, cannot fold 2:nd best hands.
Button - S-LA, decent postflop.

Party Poker 2/4 Hold'em (10 handed) converter

Preflop: Hero is MP3 with T[img]/images/graemlins/diamond.gif[/img], A[img]/images/graemlins/diamond.gif[/img].
<font color="#666666">4 folds</font>, MP2 calls, <font color="#CC3333">Hero raises</font>, CO calls, Button calls, SB calls, BB calls, MP2 calls.

I raise because I know that CO will call. I'm not impressed by MP2's openlimp. I fully expect this to be a multiway pot.

Flop: (12 SB) T[img]/images/graemlins/spade.gif[/img], 3[img]/images/graemlins/diamond.gif[/img], K[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(6 players)</font>
SB checks, BB checks, MP2 checks, <font color="#CC3333">Hero bets</font>, CO calls, <font color="#CC3333">Button raises</font>, SB folds, BB folds, MP2 folds, <font color="#CC3333">Hero 3-bets</font>, CO calls, <font color="#CC3333">Button caps</font>, Hero calls, CO calls.

hmm, I keep raising because I may very well have a pot equity edge here. I'm happy to put bets in as long as CO comes along to pad the pot.

Turn: (12 BB) 2[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets</font>, <font color="#CC3333">CO raises</font>, Button calls, <font color="#CC3333">Hero 3-bets</font>, <font color="#CC3333">CO caps</font>, Button calls, Hero calls.

No need to get fancy here right? CO raises wich means he can beat top pair. Button goes into call-down mode?

River: (24 BB) 3[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
Hero checks, <font color="#CC3333">CO bets</font>, Button calls, Hero calls.

ugh, this is where I start to feel uneasy. I do not want to get into a raising war with a paired board. KK is unlikely / impossible for Button, but TT is slightly possible. I decide to show this down as cheap as possible. I really have no clue how I should respond if I have to face 2 cold with a great risk of it getting capped afterwards.

Final Pot: 27 BB

Wise move or was I too defensive on the river?
Any other comments bout my play or reasoning behind it?