NL 25: Nutstraight am river; flush?

[potlimit888]

Full Tilt Poker
No Limit Holdem Ring game
Blinds: $0.10/$0.25
6 players
Converter

Pre-flop: (6 players) Hero is Button with 8[img]/images/graemlins/club.gif[/img] 9[img]/images/graemlins/club.gif[/img]
UTG folds, UTG+1 calls, CO (poster) checks, Hero calls, SB folds, BB (poster) checks.

Flop: A[img]/images/graemlins/spade.gif[/img] 7[img]/images/graemlins/spade.gif[/img] 2[img]/images/graemlins/spade.gif[/img] ($1.1, 4 players)
BB checks, UTG+1 checks, CO checks, Hero checks.

Turn: 6[img]/images/graemlins/club.gif[/img] ($1.1, 4 players)
BB checks, UTG+1 checks, <font color="#cc0000">CO bets $1.1</font>, Hero calls, BB calls, UTG+1 folds.

River: 5[img]/images/graemlins/heart.gif[/img] ($4.4, 3 players)
<font color="#cc0000">BB bets $1.5</font>, <font color="#cc0000">CO raises to $5</font>, Hero calls, <font color="#cc0000">BB raises to $11.5</font>, CO calls, Hero calls.

Results:
Final pot: $38.9
<font color="#ffffff">BB showed 4s Ks</font>
<font color="#ffffff">CO mucks 4c 8d</font>
<font color="#ffffff">Hero mucks 8c 9c</font>

Wie spielt ihr in so einer Situation?
Villian BB: 24/8/2,8 bei ca. 300 Händen
Villian CO: unknown