Questionable River Fold

[Kyle]

Villian in this hand is fairly reasonable. Too loose preflop but not a terible player postflop. His stats are 23.8/11.54/1.80. His river agg is 1.00 over 130 hands.

Party Poker (9 handed) converter (http://www.selachian.com/tools/bisonconverter/hhconverter.cgi)

Preflop: Hero is BB with K/images/graemlins/spade.gif, 8/images/graemlins/spade.gif.
<font color="#666666">MP2 Raises, SB calls, Hero calls</font>.

Flop: K/images/graemlins/heart.gif, Q/images/graemlins/heart.gif, 7/images/graemlins/club.gif <font color="#0000FF">(3 players)</font>
SB checks, Hero checks, villian bets SB folds.

Turn: 9/images/graemlins/club.gif <font color="#0000FF">(2 players)</font>
Hero checks, villian bets

River: 3/images/graemlins/diamond.gif <font color="#0000FF">(2 players)</font>
hero bets, viliian raises, Hero folds.

Final Pot:

[MJS]

I'm don't understand why you played it so passively - Top pair 3 handed then heads up I would think you would want to be the aggressor. As for the river, I think you should have called. He could have been betting almost anything with position. Once you've called that far I think you have to go one more.

I aslo think you should have lead out on either the flop or the turn to get some read on where your hand stood. A check-raise on the turn might also have been a better move. He would probably fold a weak hand, call a drawing hand, and reraised a strong hand giving you a better idea of what to do on the river.

[phish]

You don't think there's a 12% chance your hand is good?

Even if it's 5%, you're not giving up much expectation by calling.

Plus, what is he to make of your donkbet on the river? That 3 helped you? Unlikely. Perhaps you're on a draw and missed and bet hoping he's in the same boat and will fold his AJ. His raise may be a thin value raise (AQ) or a bluff or a very strong hand (AK or better). But the possibilities are there, and I think that your odds of winning are better than 12%.

You can safely fold this if, after her raise, she shows you his KJs or KQo, or the ever-deceptive JT.
The problem is that you are so far away from knowing what she has. She has shown aggression on every street, so her preflop raise was probably done on big cards or a pocket pair. Since there's a flush draw that didn't get there, there are a lot of hands she could raise with here that are worse than K8. The problem is that there are also a lot of valid raising hands that do beat yours. I think given the way you played the hand until the river, your best option would have been to check-call the river, as heads-up most opponents would continue betting on the river, given that your most likely hand is a flush draw. If you have been caught before folding to a river raise, then you have to be aware that the probability of a river bluff-raise is now higher.