BB is 67/18/0.67 over 40.
Mp2 is unknown (seemed pretty tight passive though)

Party Poker 0.50/1 Hold'em (8 handed) FTR converter on zerodivide.cx

Preflop: Hero is MP1 with A:club:, Q:club:.
2 folds, BB calls.

Flop: (8.50 SB) 5:spade:, T:heart:, A:heart: (4 players)
BB bets, Hero calls, MP2 calls.

Turn: (8.75 BB) 3:club: (3 players)
BB bets, Hero calls, MP2 calls.

River: (11.75 BB) K:heart: (3 players)
BB bets, BB calls, Hero?

Final Pot: 16.75 BB

With Mp2 waking up I don't think I'm good even 1 in 20 times here...
Also, how does the rest of the hand look?

Not only is he waking up, but he's waking up in a pot where two other guys have been battling the whole way, which means that a bluff is much less likely. Not to mention that the river completes most concievable draws MP could possibly have.

I would fold that river getting a lot better odds than 20:1. Not the first time, but the second time.

On the flop, we obviously raise to charge the field two cold on a draw heavy board. Once he three-bets, I think it's best to just call, as you did, because you could concievably be behind a dubious two-pair holding, and you want worse hands to keep betting at you.

I would also call down from there, but I'm wondering if raising the turn has merits once BB bets? It would charge MP (who, given flop action is most likely drawing) the maximum for his draw, and I think it's possible that we are ahead of BB since his stats indicate retardedness (given they're over a small sample though).

Raising turn is looking pretty sweet.
I read one street at a time..and I thought "cool, don't cap flop..now pop that turn..charge MP2, BB is a bad player, it's worth the risk of a 3-bet to charge/fold MP2, POT BIG.

Fold River