Just call river with a straight flush?

For sake of argument, let's say you are UTG with AKs. Forget how you would have played the hand, let's get us to the river. Assume equal stack sizes. Let's say both CO and BB are solid players that have shown down good hands.

Preflop:
UTG calls $1, 1 fold, CO calls $1, 2 folds, BB raises to $4, UTG calls $3, CO calls $3.

Flop: ($12.50) 3http://www.flopturnriver.com/phpBB2/...iles/spade.gif, 5http://www.flopturnriver.com/phpBB2/...iles/spade.gif, 4http://www.flopturnriver.com/phpBB2/...iles/spade.gif (3 players)
BB bets $8, UTG calls $8, CO calls $8.

Turn: ($36.50) 2http://www.flopturnriver.com/phpBB2/...iles/spade.gif (3 players)
BB checks, UTG checks, CO checks.

River: ($36.50) 4http://www.flopturnriver.com/phpBB2/...es/diamond.gif (3 players)
BB checks, UTG bets $11, CO raises to $25, BB folds, UTG raises to $39, CO raises to $49.8, UTG calls $10.80.

Final Pot: $136.10

After you have raised on the river then you are re-raised, do you think you are beat? Since you hold both the A and K of spades for the wheel SF, do you really think villain will re-raise you with just a queen high flush? Would you re-reraise here, or simply call? If you did raise as UTG did in this hand, after you are again re-raised, you are beat, right? What else can villain have besides the 6 of spades?

How do you play this river?

Uh, a boat? Quads? Possibly even a Q-high flush. His last bet isn't really a raise he's just putting the rest of his chips in.

In this situation he only has two hands
1)6s
2)boat

1 is more likely than 2 by the way he played the hand on flop (just call instead of reraise with 2pair/set) and his river action.

75% he has a 6s, 25% boat

That said I dont think either is a big mistake on river, since you're not deep. As played is fine, if we were deeper I'd just call the raise to 25$.

Btw, this is all based on our assumption CO is competent/solid

I think its trivial to to try to get in all your money in this spot.

I guess if more money was left the hand would be more interesting as a poker exercise. the other player had the higher SF in this hand, just one of those weird things I guess. Never seen anything like it!